2005 V6 Modded- Looking for immediate O2 sensor fix

[Josiah Worm]

Hello all.
I’m new to this forum and I am looking for a fix.
I have a 2005 V6, modified with JLT Series 2 CAI, an SCT X4 with custom tunes, pacesetter long tube and off-road y pipe, factory mid pipe, and custom fabbed cherry bomb 8” glasspack muffler. I have custom welded o2 sensors in the y-pipe, and they have worked fine since my last custom tune update in December 2018. Just this last week, August 2nd, my CEL just came on, with following codes: P0135, P0152, P0161, P0600, P1000, P2105, U0300. I have non foulers installed between the pipe and sensors. They didn’t help. I keep trying to retune my system, but that keeps throwing codes. It starts hard some times, idles rough, and after a minute of idling down rough to 700rpms, when my idle is set at 800, it dumps fuel in the system, and idle goes up slightly, and runs smoother, then the CEL. Fuel smell is terrible, gas mileage went from 22-17 almost overnight. Any help appreciated, thanks!

-Joe “Boss” Worm

 

[Josiah Worm]

If there is any more information I could give, let me know. My car was in the shop for 3 days this week trying to fix it. We used Spark Plug non foulers to try and quick fix the situation, which seemed to work for other people over Facebook. They did not work for my situation. Before this past week, my car had no problems and no codes for 8 MONTHS! If anyone has anything for me that I could do, please, get back to me ASAP!

Thank you!!!

 

[nbk13nw]

Could be a VCT solenoid. Had similar issues earlier this year. Ended up being the passenger side vct. I had already replaced them less than a year ago, so i was suprised. It was throwing 02 codes, barely running in limp mode, barely idle. Replaced the sensor and all has been fine since that time.


Or does the V6 not use a VCT / VVT solenoid?

 

[Josiah Worm]

Could be a VCT solenoid. Had similar issues earlier this year. Ended up being the passenger side vct. I had already replaced them less than a year ago, so i was suprised. It was throwing 02 codes, barely running in limp mode, barely idle. Replaced the sensor and all has been fine since that time.


Or does the V6 not use a VCT / VVT solenoid?

No, the 4.0 V6 does not use VCT. I have heard elsewhere that the Alternator can cause many types of bad problems, and still have 14V.

 

[Juice]

U0300 - Incompatible software in PCM. Specifically, throttle control. Fix this first.

 

[Josiah Worm]

U0300 - Incompatible software in PCM. Specifically, throttle control. Fix this first.

Okay? Any ideas? I’ve only had this problem a few times, and cycled the car as well as retuned it. It has gone away in the past. Should I talk to my tuner?

 

[Juice]

Okay? Any ideas? I’ve only had this problem a few times, and cycled the car as well as retuned it. It has gone away in the past. Should I talk to my tuner?

That would be a good idea, I have never dealt with that code. There may also be updates for the tuner device. If you do find it has an update, I would "restore to stock", update device and then reload tune.

Check all ground connections, specifically the ones at the right headlight/hood prop rod. I had one of those loose and it corrupted the tune I was loading.