Emissions with Long tube headers and cams

theRedStorm

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Currently have a 2005 Mustang Gt.
It has kooks long tube headers and high flow cats. I got a emissions tune from a local dyno guy here. I saw he enabled rear O2s . My Rear O2s on my scan tool read N/A. I've done multiple drive cycles. Occasionally I get p0300 for faulty cam position sensor but that is due to the cams triggering a false alarm. Could my Rear O2s be damaged and need replacing? How do I check that they are functioning?

If I have O2 extensions on the rear, could that be a reason on why my sensors won't be ready? (not sure if they are hooked up or not but I know the LTH kit came with em)
 

07Bossman

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I think "incomplete " would be the correct label if they were active.
 

01yellerCobra

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N/A means the monitor has been removed completely. Hopefully your smog place doesn't have the software that counts available monitors.
 

07 Boss

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Isn't P0300 a misfire code? Just wondering why you think its a cam position sensor that is at fault?

You need to enable the rear sensors to pass smog. It can read not ready as you're allowed one not ready but it can't say N/A.
 

theRedStorm

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How would the be removed? I have them plugged into my catted H pipe and connected properly. Could this be because of O2 extensions?
 

theRedStorm

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Isn't P0300 a misfire code? Just wondering why you think its a cam position sensor that is at fault?

You need to enable the rear sensors to pass smog. It can read not ready as you're allowed one not ready but it can't say N/A.
It's a reported false flag that happens with Hot rod cams. My tuner can turn it off if he needs to.
 

GlassTop09

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Currently have a 2005 Mustang Gt.
It has kooks long tube headers and high flow cats. I got a emissions tune from a local dyno guy here. I saw he enabled rear O2s . My Rear O2s on my scan tool read N/A. I've done multiple drive cycles. Occasionally I get p0300 for faulty cam position sensor but that is due to the cams triggering a false alarm. Could my Rear O2s be damaged and need replacing? How do I check that they are functioning?

If I have O2 extensions on the rear, could that be a reason on why my sensors won't be ready? (not sure if they are hooked up or not but I know the LTH kit came with em)

I don't know which brand of scan tool you have but there are scan tools out there that will show the ECU O2 sensor test results (ECU does a system check at every drive cycle & at a predetermined time during operation to check operational status). I can see the O2 sensor test results in my 09 Stang's ECU using either my Foxwell N301 or Autel MS808Pro scan tools that would reveal if an O2 sensor either passed or failed testing.

Yes, all O2 extensions aren't the same quality & a bad 1 can throw an O2 sensor's signal off to or cut it off from the ECU. If you have a multimeter you could run an Ohm test on the extension wiring to see if there is an issue....but don't get your hopes up too much. As for the rear O2 sensors reading N/A.....is this the rear O2 sensors readout (voltage) itself showing as N/A or is it the rear O2 sensor efficiency % (shows cat efficiency level) readout showing as N/A. If the latter then it is known that some scan tool's firmware will not read this PID & will show it as N/A. I know this to be true as I have a scan tool (Foxwell N301) that won't read the efficiency % PID (show as N/A) but I also have 2 other scan tools (ScanD 900 & Autel MS808Pro) that will read them so you might check w\ your scan tool manuf to see if there is a firmware update for your scan tool that may fix this if found to be the issue.

Hope this helps.
 

Forty61

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I’m pretty sure N/A on my scanner meant those specific sensors were off, yours would appear to be the same since you have two showing two ‘INC’ or incomplete.. for mine to pass emissions with similar mods to yours everything read OK or N/A.

If you can get those two ‘INC’ ones to go away I would try for inspection and see what they tell you, just my opinion. I’m sure someone with more knowledge will chime in.
 

Pentalab

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On my aeroforce digital gauges, I can read cat temps individually... which requires rear cats to be functioning...and enabled.
 

k_aimone

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I have Kooks long tubes/catted H/ and Detroit Rocker cams.

believe it or not BBR is the only place I found that got the tune to not kick a light with the rear O2s turned on. I had to do the non-foulers but it does pass inspection.

this was about 9 years ago, but I still get it inspected on that tune with no issues.
 

GlassTop09

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Ok, I've reread your OP & I think I know what is going on now.
Since you have an "emissions" tune flashed in your ECU now, the tuner who modded this tune has turned off/disabled these monitors (the ones that show as N/A w\ the exception of the EGR Monitor which on the 05-up Mustangs are set as N/A anyway as the ECU itself now uses the VCT system to perform this function so no separate EGR system exists) so your scan tool can see the PID's while in IM Readiness Mode but they are disabled in the tune. Your rear O2 sensors are enabled but the monitoring of them is disabled in the emissions tune (along w\ all the others that show as N/A) so you won't get a MIL on any of those monitors due to the part(s) failing as they are not being monitored by the ECU for emissions status. Only the fuel system monitor & the computer component monitor is enabled & the test results for those haven't completed yet (thus the INC). To look at the sensors themselves then look at them thru the live data mode or the component check mode, not thru the IM readiness mode.

This may get thru an inspection check IF the inspector only goes by the readouts alone & doesn't do a look up check to verify the necessary monitors needed to pass emissions based on your year, make & model of vehicle (thus why it's called an emissions tune).

Good luck.
 
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theRedStorm

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I'm gonna have my tuner make a custom tune file with all original emissions monitoring equipment enabled and see if that fixes it.

What's the default enabled monitors for a 05 mustang gt?
 

GlassTop09

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I'm gonna have my tuner make a custom tune file with all original emissions monitoring equipment enabled and see if that fixes it.

What's the default enabled monitors for a 05 mustang gt?

All of them except the EGR System monitor (already mentioned why) & Sec Air System monitor (the 05-up Mustangs also do not use an air pump to pump fresh air into the cats to promote burnoff of unburnt HC's, the ECU does this itself by using the rear O2 sensors measuring the oxygen level output from the cats to maintain the necessary oxygen levels needed to promote HC combustion within the cats thus no air pump needed). The A/C Refrig System monitor is used to monitor the HVAC system operation & is not necessary to pass emissions per se, but is needed to protect the A/C compressor if the HVAC system loses refrigerant.

You're allowed to have only 1 monitor to be INC to pass emissions, not 2 or more INC's w\ NO faults that lit up the MIL. This is what the inspectors are looking for when they plug into the OBDII port to check the ECU concerning emissions & is why you should always scan your ECU periodically to check AND know how to do a proper drive cycle procedure to ensure that all monitors complete their tests.

Here is a copy of the FoMoCo approved drive cycle procedure to properly reset PCM monitors for emissions below if you don't already have it.

Hope this helps.
 

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theRedStorm

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New tune did the trick. Now I get p430 (cats below efficiency). Next question for yall, what do you recommend for passing? I see mini cats O2 extensions 90 degree ones. Seems like those do the trick. Any other recommendations or is that the way to go?
 

GlassTop09

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New tune did the trick. Now I get p430 (cats below efficiency). Next question for yall, what do you recommend for passing? I see mini cats O2 extensions 90 degree ones. Seems like those do the trick. Any other recommendations or is that the way to go?

Ok, now is the P0430 code the only 1 you're getting? Not getting the P0420 code as well? If you don't already know, the P0430 code is for B2 cat inefficiency (driver side), P0420 code is for B1 cat inefficiency (passenger side). If you're not getting a P0420 code then your issue is w\ the B2 cat only (might check the pending codes to see if P0420 is there--means that ECU saw B1 cat dip below the 92% min threshold momentarily but didn't stay past the time threshold for ECU to flag it as permanent).

After checking to see what the stipulations are in the area where you've registered your car (you probably already know but I had to say), I would check the connection between your B2 header & cat to ensure that there isn't a leak there then check the rear O2 sensor for leaks in the bung (does happen) or for sensor functionality (both in the component system check to see if B2 rear O2 sensor is passing\failing drive cycle system tests here & in live data to see the actual B2 rear O2 sensor operation to see if the B2 rear O2 sensor voltage is tracking w\ the B2 front O2 sensor STFT switching pattern while in closed loop along w\ the FF (freeze frame) data to see where the B2 rear O2 sensor readouts were when the ECU set the P0430 code....main items to look for the O2 sensor voltage readout whether hi--above .7 or low--below .5, cat operating temp, cat efficiency % readout. Also check car's wiring looms between sensor to ECU for integrity). Could be setting from excessive oil burning from the PCV system (routes into the driver side of intake manifold just in front of cyl #5 intake runner--#5, #6 & #7 cylinders would get the brunt of any oil that comes thru here--cat efficiency maintenance is another good reason why to use a good oil catch can on a N/A 4.6L engine let alone FI along w\ a good grade of full synthetic motor oil....dino motor oil has a tendency to foam up/vaporize more under heat when agitated & is easier to carry in air stream thru the PCV system than full synthetic motor oil). May also check your driving habits...if you're prone to lugging the engine (pushing throttle past 25%-30% at low engine speeds in 5th gear in certain conditions....not that hard to get into w\ a TR3650 manual trans & a performance tune in ECU) this can set off a P0420/P0430 code as well (know this 1st hand....this is the only reason why I installed CEL eliminators on my car, otherwise my car wouldn't need them & I'm running the same Kooks exhaust setup as you are....but this was before the Lunati VooDoo cam install & following dyno tune--was running the OEM cams at the time--so may be different now but won't know it as I already have CEL eliminators installed. I looked into the option of going w\ the higher cost Kooks Green Cats which are 49 state legal but conferring w\ a well-known reputable national shop they said that the reg Kooks Hi Flo cats are just as good as the Greens but aren't certified--why they're cheaper) due to excessive cat temp output....not hurting the cats per se (Kooks Hi Flo Cat substrates are rated for 1500*F max operating temp range) but this WILL affect the rear O2 sensor operation causing them to operate erratically and/or fail when they get too hot over some amount of time (this is the main reason for cat inefficiency codes using FI, once the sensors go the cats will shortly follow). Lastly might check fueling for overly rich situations while ECU is in closed loop but mostly can be disregarded if car has been tuned as tuner should verify this AS LONG as there are no mechanical failures present (faulty injector(s), fuel pump regulator, etc).

Giving you some things to look into before falling back to using CEL eliminators. First off, IMHO leave the cheap stuff alone & use quality parts from reps who do actual design testing/usage (yeah they'll cost more). The CEL eliminators that were shown in this thread are very good parts that are designed/tested under actual racing conditions & will pretty much work w\o issue as long as you've covered the basics (no vacuum leaks, excessive oil\coolant burning, exhaust leaks ahead of\at sensor location, excessive fueling, wiring integrity, etc). I have the 90* sections w\o the mini cat sections of the Big Daddie's Garage CEL eliminators installed on my car & they work flawlessly but you'll have to lower the mid pipe to get them installed (to clear the unibody and\or trans crossmember). There is a 90* 2-piece CEL eliminator w\ a mini cat in 1st section that can be installed w\o dropping the mid pipe...can be found on eBay (can't remember the name at the moment). IMHO you'll want these parts built out of SS instead of reg steel to prevent eliminator fouling from internal rust buildup from condensation (which also costs more) as well.

1 more thing.....if you always are keeping your foot into it all the time then save yourself some time & keep spare replacement cats on hand as you'll need them sooner than later....CEL eliminators ain't gonna save you from this if you're keeping the ECU in open loop a high % of operating time w\ a performance tune flashed in the ECU...……..

Just saying...…………………….

:)

Hope this helps you out.
 
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GlassTop09

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While on this subject....……………...

The best LT header/mid pipe combo to use when looking to run w\ cats is the mid-length LT header/mid pipe combo as this setup keeps the cats closest to the engine's exhaust ports than all the rest thus has the best chance of cats working like OEM. The farther the cats are from the engine's exhaust ports the greater the odds of cat failure due to operational internal temp loss (read fouling/clogging here due to ineffective HC burn due to too low operating temps inside cats). Tis why the cats are installed as close to the engine's exhaust ports as possible by design.

Of course, if cats aren't gonna be used then it doesn't matter.

FYI.
 

theRedStorm

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Ahh I didn't post it. Yes I'm getting both p0420 and p0430 codes.
I plan to go catless with a catless X pipe but currently have a catted H pipe from kooks on my car for. Emissions. My emissions expires end of August. I wanted to knock out the emissions early so I don't have to stress last minute hence why I'm doing it now.
 

GlassTop09

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Ahh I didn't post it. Yes I'm getting both p0420 and p0430 codes.
I plan to go catless with a catless X pipe but currently have a catted H pipe from kooks on my car for. Emissions. My emissions expires end of August. I wanted to knock out the emissions early so I don't have to stress last minute hence why I'm doing it now.

Ok, now this clears up some......strictly due to the performance tune side of things as these hi flow cat substrates aren't as dense as the OEM's are (less total contact area to achieve the higher flow rates thru them on less deltaP) so they tend to get overwhelmed on both heat and\or HC & NOx emissions due to increased exhaust volume output thru them (NOx from higher cylinder operating temps, HC from higher ratio of unburnt fuel present in exhaust & higher than normal cat operating temps can start degrading the substrate surface contact area where the chemical reactions occur to break up the NOx & HC) vs OEM (even at the same AFR) so the usual pattern is that both P0420\P0430 codes will set once the exhaust output exceeds the cat's capacity to do it's job (usually from the rear O2 sensor readout starting to track w\ the front O2 sensor's switching pattern in CL operation which indicates to the ECU that the cat(s) are not working). At this point you would have to use cel eliminators or detune your engine so the exhaust outputs fall back within the cats capacity...the latter isn't an acceptable option for us gearheads......

These Big Daddies Garage CEL Eliminators work very well. If memory serves me, the 90* sections alone were designed to fit in tight areas & handle larger engine's exhaust volume output, the mini cat sections were designed to work w\ high performance catless exhausts (turbo or non-turbo) used on 1.6L to 6.3L engines so when both are used in tandem you get the best of both. They do cost more than most, though.

There are cheaper versions out there, of course so it's up to you from here.
 

Pentalab

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The Big Daddies Garage 90 deg cel eliminator's and also mini cats are made from quality SS. Everything else will rust. Their inline cel eliminator's can be added to the 90 deg units, if extra length required.
 

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