JohnStr

I was having problems last week, no codes, just not a full 20psi, and boost surges. I would on occasion, have black smoke leave my exhaust, enough to cause concern, I don't think so, but smoke is smoke. I bought a new MAF, and race N75. When I put the n75 in last week, it seemed to straighten up the surges, but they came back. I didn't have a full 20psi at all today. I haven't been noticing smoke, but I have noticed dirty tail pipes. I got in this afternoon and DTC 17535 (system too rich). I replaced the MAF this morning, and had no problems driving earlier. I do not know what else could be doing this to me. I also have been noticing a rough idle the past few days. I was told it was normal being a big boost application with larger injectors on a 4cyl. Either way the secondary air pump code came back today too (16795). I know to test that individually, but I'm more concerned with the air/ fuel. Any one have suggestions? (2001 A4 1.8T QM, T-28 1.3bar, stock IC, Borla exhaust w/ DP).

Whoismario

Maybe you have a boost leak or you FPR is set too high?

auditunerb5

You need to pressurize your system to check for leaks. Search AWE pressure test.

JohnStr

how can I check that? I ran some tests and my engine is rich until I get around 5krpms it leans out. I'm running really rich, 1.24+ then back to .78 up top running lean.

auditunerb5

I hope someone can chime in on this. But from my understanding 2001+ cars the lambda is opposite of 2000 and older? Meaning your readings correspond to normal lambda curve which higher is LEAN and lower is RICH.

If this is true then you are lean down low and dumping fuel up top!

Whoismario

Search for doing a pressure test. But at the very least start with a visual check of the system.

JohnStr

if that is true, its really bad that I drive my car... isn't it?

JohnStr

MY DTC says rich, not lean....

auditunerb5

Do you hav a VAG?

Check block 032 fuel trims...

Do you have AIM?

Here's the link to pressure test<ul><li><a href="http://awe-tuning.com/media/pdf/27t_pressure_tester.pdf">http://awe-tuning.com/media/pdf/27t_pressure_tester.pdf</a</li></ul>

JohnStr

My fuel trims, under WOT throttle only are as follows:
0.9 -24.2
0.9 -25
0.9 -25
0.9 -25
There are the same numbers that go on, you get the idea. I spoke with PES they told me that I'm rich by this data. I'm not driving hard since this light came on. Is that why you said you'd rather be rich up top than lean? I'm barely boosting (5-10psi, if 10) till I get this fixed...I'm pressure testing on Friday, or Saturday.