Test Pipe=Rich???
Jun 22, 2007, 06:37 PM
#17
Well, unless you had more knock in the TP run or you also changed to a different filter (to mess with MAF readings), then I can't explain it right now.
There has to be some other compensation that is going on. The test pipe should have increased your mass airflow, and thus your load. Something just doesn't make sense.
Eric
There has to be some other compensation that is going on. The test pipe should have increased your mass airflow, and thus your load. Something just doesn't make sense.
Eric
BTW, the testpipe is a resonated 3 inch one. Would that make a difference?
Jun 23, 2007, 02:46 AM
#20
Do a free air cal (with sensor in air)
nevermind
The only thing you change was the test pipe?
Maybe the test pipe change the path of exhaust or something or you had a leak before you installed it
nevermind
The only thing you change was the test pipe?
Maybe the test pipe change the path of exhaust or something or you had a leak before you installed it
Last edited by C6C6CH3vo; Jun 23, 2007 at 02:49 AM.
Jun 23, 2007, 04:38 AM
#21
if you have a cat, youre going to get leaner readings than without one..... youre reading unmolested air with the test pipe...
with the cat youre obviously reading air that has gone through a brick that is designed to filter emissions!
we see that all the time on the dyno...
cb
with the cat youre obviously reading air that has gone through a brick that is designed to filter emissions!
we see that all the time on the dyno...
cb
Jun 23, 2007, 08:25 AM
#23
if you have a cat, youre going to get leaner readings than without one..... youre reading unmolested air with the test pipe...
with the cat youre obviously reading air that has gone through a brick that is designed to filter emissions!
we see that all the time on the dyno...
cb
with the cat youre obviously reading air that has gone through a brick that is designed to filter emissions!
we see that all the time on the dyno...
cb
Jun 23, 2007, 09:57 AM
#27
1. I noticed that when I would try and richen the fuel map in the 3500-4500 rpm rpm the car would still run lean. It was not as responsive as it should have been to fuel changes. This continued to happen even after I turned off lean spool. The car was more responsive to fuel changes on the high end of the rpm, however. This tells me that the exhaust leak was not large enough to contaminate the AFR when the exhaust gases are moving at a fast rate, but it was large enough to contaminate the results on the low end.
2. When I isantalled the TBE w/HFC, I re-used the same worn out gaskets, since I did not have any new one. When I installed the TP, Iused brand new gaskets that came with it.
3. When I removed the HFC, I noticed some soot residue on the heat shield above the HFC. That is a telltale sign of a leak.
That is the best explanation that I have so far.
Jun 23, 2007, 10:02 AM
#28
I would say that nails it on the head then. Just chalk it up to an exhaust leak and start tuning now that you have everything working nicely and found the cause of this issue.
Another quick question: Did you notice your idle AFRs any leaner with the HFC than with the test pipe? When I used to have a leak at my downpipe a long time ago, it would show up as lean idle AFR, but as you mentioned, with higher velocities and volumes of exhaust gases at WOT, it wasn't much of a difference. That was also a quick indicator for me of an exhaust leak.
Eric
Jun 23, 2007, 10:34 AM
#29
I made nothing of it, but in retrospect, it all makes sense.
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