P0174 Code, only when hot out......

**jfl330** · 06-12-2013, 03:14 PM

I drive to work in the morning and everything is perfect. STFT's ~ 0, LTFT's low single digits, all O2 sensors switching normally. In garage all night, ~ 75F.

Go to drive home, sits in sun all day, ~ 93F, Bank 1 normal, Bank 2, STFT >50, LTFT 25, O2B2S1 never goes over 0.2V. Tail pipes black, runs like crap, idles like big cam.

Any ideas?

Already replaced, wires, plugs, coil packs, had injectors cleaned and flow tested, replaced pcv system, all O2 sensors, no vacuum leaks, no exhaust leaks.

Jon

**pajeff02** · 06-13-2013, 02:32 AM

I presume it was the exact same issue before all the parts were swapped out?

**jfl330** · 06-13-2013, 04:52 AM

Originally Posted by pajeff02

I presume it was the exact same issue before all the parts were swapped out?

Yes, replaced parts chasing the problem.

I have been driving problem free for a few months, until it got hot recently.

**b.lee** · 06-13-2013, 04:58 AM

Stock tune or?
Any mods?

***SMWS6TA*** · 06-13-2013, 10:09 AM

Have you cleaned the MAF?

MAF could be on your the way out, get it tested.

**jfl330** · 06-13-2013, 03:25 PM

Originally Posted by b.lee

Stock tune or?
Any mods?

Diablo tune, bbk intake and tb, slp lid, flowmaster cat back.

**pajeff02** · 06-13-2013, 05:43 PM

I have read about sealing issues with the BBK intake.

***SMWS6TA*** · 06-14-2013, 08:23 AM

Originally Posted by pajeff02

I have read about sealing issues with the BBK intake.

**Naaman** · 06-14-2013, 09:52 PM

So, most likely, the ambient heat is causing the seals/metals to warp, ruing A/F ratios... ? Or just a coincidence that it started happening as the outdoor temps heated up... ?

***SMWS6TA*** · 06-17-2013, 11:29 AM

Well you have 2 things with the BBK intake. 1st is you're going to get heat soak just because of the material it's made from. The second because of heat soak it can distort cause vacuum leaks. I know a guy that swears his BBK runs awesome and has no issues.

I have a suggestion for you if you still have your LS1 intake. Swap it back over to the LS1 intake, see how it runs. It doesn't take long to do and can be done in your driveway. It won't effect any tuning issues if that's a worry. If you do do it and notice it running better then you have found your problem.