Car is Stage 3 (K04'd + e85).
So I have been tracking a random P1177 and P1178 (Bank 1 and 2 - O2 (Lambda) Correction Behind Catalyst: Control Limit Reached) for a couple months now. Clear them and they come back after ~30 miles. Not a big deal they have not affected performance. Rosstech states it can be caused by exhaust leak or intake leak.
I did originally have an exhaust leak so I had my SSAC system welded completely together (except for Downpipe to Cat V bands). Confirmed no leaks. Light came back just as frequent so I turned my attention to intake related issues.
Fast forward to 2 weekends ago. I build a boost tester and boost test my system. Builds to 15psi barely and I can hear an audible leak coming from green check valve near F hose. Swapped my diverter valves with the parts car as well (710N). I continue driving the car (thursday) and it boosted and had power but it would studder a bit after letting off a hard 3-4k pull in 5th and 6th (congested traffic highway driving). Drove home no issues but long term trims showing rich condition (-9 and -10%).
Fast forward to today. I received the green check valve, install it, and do yet another pressure test. Pressure the system to 15PSI (which it easily reached and could go more), let go, and it slowly lost pressure over 28 seconds. Yay, seems everything is good. It retained pressure way better than the pre-check valve test. So I jump in the car and head down the street for some spirited driving... To my dismay the car felt like my old VR6. I tried to boost as much as possible without going over 4500 so I wouldnt mess anything up, however, it wont hit more that 4 psi. The car is a complete dog. Head home and grab my laptop for some logs and start out down the road. Did a quick run and came back.
Check my logs and Requested boost is fine. Tells me the ECU is not in limp and is trying to tell the turbos it wants boost. My MAF readings are crazy and I dont know how to explain those unless it is directly correlated to the lack of boost.
First thing I did was test the N75. Pulled one from my parts car and swapped. Same issues. unhooked the WG line entirely, same issues. Does anyone have any suggestions?
Here is my entire Me7 Log - Click here
Resolved!!!!
Here's the series of events:
1) Pulled vac lines from DV's and went for a drive. Pulled out on to the main road and to my dismay I boosted to ~4 psi. I thought to myself how ridiculous it is that the car runs fine, no smoke, no sounds, good idle, and the damn thing just doesnt want to boost. So I said fuck it lets try to make whatever is wrong worse so I can know what is happening. I give it another WOT to about 4500 and it got better with ~8. I thought wow, whatever it is it is getting better. Gave it another WOT and managed to get 11psi. WOW! Head back home to make some adjustments.
2) I put it in the old DV's that I removed (vac lines still off), drove it down the street and managed to squeeze 15psi. Ok now I am happy but sad that I have not figured it out. So I thought I was just getting a soft code and the car was in limp. Drive home and scan. No codes... put the capped vac lines back on and give it a go down the road. Bam, 23PSI, back to stage 3 levels!!!
Lessons Learned:
1) If you have to do more than one thing at a time and they are simple tasks, do them one at a time. This helps you diagnose issues much easier. I should have followed that principle since I usually follow it during my work. I am a software coder and I always try to do things in chunks or else you get lost in layers of code.
2) The greatest of all: Dont fix things that arent broken. I proactively swapped my DV's during my boost leakdown test because they were installed on my parts car and had less than 500 miles on them, however, it was not for any reason other than preventative maintenance. Refrain from doing this if you can. And if you have to do it, follow step 1 very closely.
Big Thanks to Corradovolksb and rguil for the suggestions. Now I understand the N80 and N249 much better than I did before. That self study is pretty good material.
Here's the series of events:
1) Pulled vac lines from DV's and went for a drive. Pulled out on to the main road and to my dismay I boosted to ~4 psi. I thought to myself how ridiculous it is that the car runs fine, no smoke, no sounds, good idle, and the damn thing just doesnt want to boost. So I said fuck it lets try to make whatever is wrong worse so I can know what is happening. I give it another WOT to about 4500 and it got better with ~8. I thought wow, whatever it is it is getting better. Gave it another WOT and managed to get 11psi. WOW! Head back home to make some adjustments.
2) I put it in the old DV's that I removed (vac lines still off), drove it down the street and managed to squeeze 15psi. Ok now I am happy but sad that I have not figured it out. So I thought I was just getting a soft code and the car was in limp. Drive home and scan. No codes... put the capped vac lines back on and give it a go down the road. Bam, 23PSI, back to stage 3 levels!!!
Lessons Learned:
1) If you have to do more than one thing at a time and they are simple tasks, do them one at a time. This helps you diagnose issues much easier. I should have followed that principle since I usually follow it during my work. I am a software coder and I always try to do things in chunks or else you get lost in layers of code.
2) The greatest of all: Dont fix things that arent broken. I proactively swapped my DV's during my boost leakdown test because they were installed on my parts car and had less than 500 miles on them, however, it was not for any reason other than preventative maintenance. Refrain from doing this if you can. And if you have to do it, follow step 1 very closely.
Big Thanks to Corradovolksb and rguil for the suggestions. Now I understand the N80 and N249 much better than I did before. That self study is pretty good material.
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Originally Posted by f4m0u5
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