background: installed ebay-xs power headers on my 02, went to dyno, produced poor numbers and a bad a/f curve. removed those and installed hot shot headers, with both primary o2 installed. dyno today gave me meager 206hp. but i am more concerned with my lean a/f and would consider that a major bottleneck not only in my peak numbers but in the health of my engine.

1K. 15
2K. 14
3K. 13.5
4K. 15
5K. 16
6K. 16

now is this being caused by faulty o2 sensors due to the extended wiring? could my fuel filter or fuel pump be dying? body has 53K only 20K on engine.

 

O2 sensors have no ay so when WOT .. so that's not your problem. You need a SAFC-ii or something similar. What type of dyno was it? Do you have the run files if it was a dynojet?

 

wow 206hp is real weak for a 6spd with headers....u should dyno AT LEAST 220 if not 225-230ish...

it can be fuel related...why dont u try running a fuel pressure test to see if your fuel pump is in working order....it could be your fuel filter being majorly clogged up as well....do u suffer a HP loss during daily driving? any knocking at any RPM? how about flashing SES? if it flashes then it means your knocking/misfiring

 

dynojet. do not have the run files. i have an safc2 that was supposed to go in my supra, but there has to be a solution before i install that. theres guys out there untuned with headers on an 02 still not running that lean.

ses does not flash. hp loss due to heat, each of the three runs was 4hp less than previous, but unnoticable in daily driving. i might consider a walbro and inline filter as my next step instead of going oem.

 

Low power is consistent with excessively high afr. It takes fuel to make power. Maximum power is produced in the 12.5-13.5:1 afr range.

If your power had been more normal I would have suspected an air leak somewhere, like at an 02 bung or the header gasket that would have given a false lean reading.

If your afr is really that high, either your headers are doing a truly exceptional job of improving air flow (in which case you can use a SAFC to adjust afr downward and get power back), or you have an intake leak after the maf.

 

never touched anything after the maf.

i suspect my gradually lower power production on three runs due to heat buildup to be a direct representation of my lean condition as well. wot run, egt goes up, pwr goes down.

i know the safc could fix the problem. i am just wondering if its the fuel pump, filter, and injectors that are starving the engine. either dirty or malfunctioning.

 

H02S1 HTR B1, P0031

I will replace that o2 sensor, find a fuel pressure gauge, then install the apexi tomorrow. Maybe get it tuned on saturday and see where I am at. Let yall know where I stand after the problem is solved.