Lots of codes...where should I begin?

[pjk91]

Engine: 70k boosted miles on a LE5

I think most of these could be related...where should I begin the troubleshooting?? Completely overwhelmed. I uploaded my tune so you guys can take a look.

Symptoms:
- Especially when the a/c is on, idle bounces around upon taking it out of gear (off load) and coasting to a stop
- Misfires most between 40-50mph under light load (-10,11,12 vac pressure)
- KR in boost @ 3800rpm or higher

Compression test results were 120 across the board. When not in boost, AFRs are fairly steady between 14.6-14.8. In boost, they seem ok but I don't hit it hard because I can't get rid of the KR.

Almost seems like the car won't hold it's tune. I'll tune it, it will run great for a week and then "learn" something and it slowly deteriorates to its current condition.

[ECM] P0101 - Mass Air Flow (MAF) Sensor Performance (Old) (History) (Immature)
[ECM] P0106 - Manifold Absolute Pressure (MAP) System Performance (Old) (History) (Immature)
[ECM] P0121 - TP Sensor Circuit Insufficient Activity (Old) (History) (Immature)
[ECM] P0172 - Fuel Trim System Rich Bank 1 (Old) (History) (Immature)
[ECM] P0300 - Engine Misfire Detected (Old) (Immature)
[ECM] P0420 - Catalyst System Low Efficiency (SES) (Old) (History) (Current) (Immature)
[ECM] P0442 - Evaporative Emission (EVAP) System Small Leak Detected (Old) (History) (Immature)
[ECM] P0101 - Mass Air Flow (MAF) Sensor Performance
[ECM] P0106 - Manifold Absolute Pressure (MAP) System Performance
[ECM] P0121 - TP Sensor Circuit Insufficient Activity
[ECM] P0172 - Fuel Trim System Rich Bank 1
[ECM] P0420 - Catalyst System Low Efficiency
[ECM] P0442 - Evaporative Emission (EVAP) System Small Leak Detected

[Iam Broke]

If you have never replaced the 02 sensor in 70k miles, I'd start there since it's popping a rich code. So many codes all at once or did they accumulate over time?

If the engine has been pulled or the main fusebox out for a clutch, ect, I'd check all the connector plugs & grounds.

The compression seems pretty low, were you using a long hose & adapter?

[pjk91]

Thanks for the reply

O2 sensor, should I replace the one before or after the CAT? Which one would throw that code? I'm guessing the one before the CAT.

They have been accumulating over time. I had the clutch replaced two years ago, I don't believe that is the issue but I'll check it out.

As for the compression, I had the TB closed. That could be why the numbers are low. The hose was 6-8" long to the gauge.

[Iam Broke]

The ECU opens the throttle plate a bit on my LNF during cranking, so I doubt it will change much on yours, I tried it both ways and made no difference. On the LNF with a 16" hose I read 165ish on all 4, that's why I thought yours were low. Did you crank it for about 10-15 sec each cyl?

It would be the 1st 02, but there are probably other issues. Look for cracked vac lines or something loose if it changes constantly. It's hard to diagnose over the interwebz.

Clear the codes and see what pops first and let us know.

[Leafy]

I'd clear the codes and just turn off all those emissions ones just to rule those out. Who knows wtf the emission codes actually do inside the pcm, I've seen some weird shit from them.

[imphat0260]

Your MAF looks a little choppy, and the transition between the lo/hi MAF tables is not the smoothest. Also, it appears you are using the the 2.5 Tmap based of your sensor linear/offset. Also, are you running a CAT? Your COT tables are set to disabled, but your DTC for P0420 is set to report on 1st error..... Also, how did you come up with your fueling tables?

[pjk91]

I am running a CAT. Its been a while, but I think what I was trying to do was disable the P0420 code completely because I thought when you disable the COT ( and I don't know why you should/shouldn't...) it would throw the code.

I'm using the 2.5 TMAP.

How do I make the transition tables (which ones are they?) smoother?

Fueling tables: I had someone help me with those. I'll be honest, it's been about a year since I looked at this. I don't recall how we came up with those numbers. I have 42lb injectors in there right now.

Yeah, I need some help with this. Someone on CSS.net told me to check the voltage at the sensors MAF and MAP to see if they're anywhere near 5v as they should be.