UPDATE: I passed emissions barely, but I'm having some knock issues. Please see 2nd page for log file (post 19) I would really appreciate it!!
Please
92 VR4
So I failed emissions at idle and am looking for a little advice on how to pass this thing.
Idle mode limits are: 220 HC (PPM) and 1.20 CO (%). I failed with 372 HC (PPM) and 0.58 CO (%).
I don’t know if it matters but I passed at “cruise” which means just revving in neutral due to being un-testable on the dyno. Limits were the same but passed with 56 HC (PPM) and 0.47 CO (%).
Now I don’t know what any of that data means, besides the obvious that I’ve exceeded a limit for something (hydrocarbons???) and thus failed. Now I’m hypothesizing that the problem is my very rich condition at idle. Low fuel trim is around 82-84% at idle, while mid and high fuel trims are in the mid-high 90’s. I don’t know how I can fix this rich condition. I currently have a hot wired fuel pump WITH an AEM AFPR. I installed the AFPR to correct this issue and after installation it did bring the high fuel trim down from ~120% to ~98%, but the low trim remained the same.
Other potential causes: I have gutted pre-cats, but still have my main cat. I have a vac redux including EGR delete. I’ve passed emissions despite these things in the past. My oxygen sensors are cycling well, but never seem to spike above .9 V. Again, I’ve passed like this in the past although it’s something I think needs to be worked out.
On top of this, the car WAS sitting for maybe 20-30 minutes before the test; I’m thinking this may have been enough time for the main cat to cool down and not work as well during the test?
Now if you have any suggestions to help me out here I’d be very grateful. The ideas I’ve come up with are to make sure the car has been running more recently to make sure the cat is hot; to lean out the fuel via AFPR (by the way pressure IS correct according to my gauge); or to get to the inspection location and remove the battery negative connection in order to reset the fuel trims. Feel free to critique these ideas. I plan to test again tomorrow morning.
Sorry for the novel, and thanks!
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