Help 2005 mustang gt running bad

[Exile918]

We had swapped the auto trans for a manual, got a used manual pcm online and got keys flashed for it. Car started but it's not running properly now. The dealer mechanic said it's running lean and it's throwing Code P2198. I checked the o2 sensors with multimeter and they seem good. They worked fine before the swap. The car feels shaky and runs like it's misfiring. The mechanic checked the air filter indicating that maybe there not enough air going in. Like mi said everything in the car was fine. I did swap the auto harness for a manual but the with my dads obd2 scanner nothing else pops up but p2198. Man I'm bummed out. Any help here I would really appreciate it.

 

[nbk13nw]

I just went thru several months trying to figure out why my cold start idle was low and rough. Burning rich at idle. Loss of power and just generally not running well. I finally pulled the throttle body. Backside was full of carbon deposits. Cleaned and reinstalled. Idle is back to normal... no more running rich and power is back. It cant hurt and only takes a few minutes.

 

[stkjock]

Check the wiring by the trans tunnel to be sure no wires got pinched.

 

[Exile918]

I'll check the intake on the car see what we find. Is there any way to find out if the used manual pcm I bought had a tune installed on it?

 

[TexasBlownV8]

Check the wiring by the trans tunnel to be sure no wires got pinched.

+1. Check the wiring between the o2 sensor and main harness, as well as the harness all the way to the pcm. The harness could be damaged, pinched, or nicked.

It is possible one of the sensors got damaged during the swap. You could switch the front sensors from side-to-side, clear the codes, and run it again, and see if the same code comes back. If the same code comes back, it is likely an issue in the harness; if the code changes to a xx96, the sensor is bad.

You could do a catalog of the o2 signals, and if one is completely missing, that would also point to a damaged wire.

 

[Exile918]

I think it said p2196 pending or something. But it threw P2198 for sure and it says running rich or it's stuck rich.

 

[thump_rrr]

Out of curiosity what year is the car and what year is the PCM?

 

[Exile918]

Car, harness and pcm 2005

 

[thump_rrr]

Car, harness and pcm 2005

Good because 2007+ is not the same as 05-06.
Was the O2 harness disconnected during the swap?
Is it possible the harness got flipped around left and right?

 

[Exile918]

Thump that was the first question we asked ourselves. I'm actually looking at the auto harness and seeing if maybe we did reverse the o2 connectors. The thing is when I installed the wiring harness It sorta just fell in to place if unknow what I mean.

 

[Exile918]

We're jacking the car as we speak and to take closer look at the 02 sensors. We're looking at the greens ones upper sensors. The only distinction I know of is that one of the green o2 sensors has a bend on the harness part with a plastic clip and that one I connected on the passenger side.

 

[thump_rrr]

We're jacking the car as we speak and to take closer look at the 02 sensors. We're looking at the greens ones upper sensors. The only distinction I know of is that one of the green o2 sensors has a bend on the harness part with a plastic clip and that one I connected on the passenger side.

A bit of info for you
Connector C171 Passenger Side Front O2#11 GY/LB RD/WH
Connector C142 Passenger Side Rear O2#12 RD/LG WH/BK
Connector C172 Drivers Side Front O2#21 RD/BK YE/LB
Connector C141 Drivers Side Rear O2#22 VT/LG TN/YE

BK=Black
GY=Grey
LB=Light Blue
LG=Light Green
RD=Red
TN=Tan
VT=Violet
WH=White
YE=Yellow

 

[Exile918]

I'll be dammed.. If those wire colors u gave me tell the tale then for sure I crossed those front o2sensors. I'm gonna swap those two. U think this is causing the car to run so weak and shaky???

 

[Exile918]

I meant making the car run rich ?

 

[thump_rrr]

wouldn't be the first time.

 

[Exile918]

We'll gents when ahead and swapped the 02 sensors and boom running beautiful. Now I can say the swap was a success I went ahead and cleaned the throttle body as we'll so couldn't be happier. Thanks again fellas

Ramon

 

[Exile918]

Good call thump the sensors were flipped much appreciated

 

[thump_rrr]

Good call thump the sensors were flipped much appreciated

Glad I could help.