My mods
Megan Racing 2.25 Exhasut sytem, no cat
DC Header 2'
Wiseco 81.5 mm Pistons Compr 11.8-12.25
-Camshaft from ITR
-Valve Springs & Retainers from ITR
-cam gears AEM
CAI

How many HP I should get from that modyfication?? I have problem with AFR. from 900rpm to 4000rpm AFR is good beetwen 12.5-13 above 4000RPM AFR is 8-9 why ?? I have stock ECU OBD1. What I sholud change ?? I changed o2sensor and AFR is still bad :/ maybe my mods it's no good ??

 

your O2 only checks the AFR for idle and light throttle. at wide open throttle, the engine runs off the ecu fuel maps. my two cents, get tuned for your mods or contact phearable.net (he's on here as mtber) to get a chipped P28 for your mods. by the way, how are you reading your AFR?

 

Sounds like your ecu is seing detonation and dumping fuel in, you really need to get that setup tuned, Atleast get a wideband and vafc

 

I'm reading by wideband oxygen sensor