MY01 ap1 i was driving last night and i decided to look at the wideband 02 at WOT in 3rd from 5k rpms. im reading 13.0 until vtec and then 14.8-15.0 at vtec, i get this massive spike. and now throught vtec until 9k rpms its like 13.7-14.0? with no tuning? i have k an n fipk intake and t1r 70 v3 single and test pipe. i have a vafc2 because i needed to trim some off up top around 8500-9k which i did and thats reading 12.8. should i be afraid to drive the car before i do any kind of tuning? ap1s run rich, im kinda lost.

 

did u calibrate the wideband before you installed it? it needs to know what 14.7:1 is before it can tell u what your at. the vtec bump happens, but it should drop right after, not stay at near 14.0.

 

yeah i know the vtec spike is normal im just worried about that whole staying at 14.0 part.

 

With the mods you have on, you might indeed be running leaner than stock. We've seen this happen over and over again to people with bolt-on's running lean.

And yes, even though 00-01 AP1 runs slightly richer than others, but not by that much. When you run a 70mm single with TP, that's a pretty drastic change to the car's exhaust system.

If you were that worried about it I recommend couple cheap solutions.

1. Get one of those AEM FPR and get a fuel pressure gauge, and slightly increase your fuel pressure. And get it to where your AFR is down to a range you are comfortable with.

2. Put your cat back on for now until you do find yourself a tuning solution.

 

now with a fpr will it make me run rich everywhere? alla the time or will it just fix my solution

 

couple things you could do. put a greddy emu in with slightly bigger injectors and retune. or you could get adjustable fpr and raise pressure slightly, then tweak tune by removing fuel with vafc.

 

Like what camuman said.

But just using the FPR, it will make it slightly richer across the entire curve, but that's really not a bad thing since you're saying you are running lean from vtec to red line. You probably will gain some power by adding a bit more fuel.

Also keep in mind that like most FPR like the AEM ones, you could either have it set at a fix psi, or you could hook it up to the vacuum and the pressure will increase according to your manifold pressure. You can play with both to see which one gives you better results.