so i have been posting almost weekly about how my car has been running very slow compaired to what it used to and a dsm guy told me that he was not too familiar with evos but my problem could be a bad o2 sensor because i run race gas a decent amount. however, i have the perrin cat delete with the o2 fix so i was wondering if that actually could be a problem that i should look furthur into. if you havent heard the story about my car it has been acting up, it lost 6mph in the 1/4 with weather, track, and mods the same within a period of a few weeks. its not my clutch, plugs, compression, or a boost leak, so i am starting to narrow it down slowly. this idea about the sensor sparked my interest and i wanted to know if something like that could cause that much of a problem. also my mods are turboback, 272s, intake, ic piping, boost control, and dynoflash custom tune. my car has seemed to be running completly normal except for feeling slow, no wierd noises or bad feelings during driving. thanks for any help again

 

i don't know it its your o2, but if it was it would be the pre-cat o2 because thats whats sending signals to the computer, i'll do some research on this but i have never heard of anything like this

 

if it wasnt the o2 do you have any other suggestions

 

do you have a wideband? if you do then check your air/fuel it should be off if your o2 is bad

 

Race gas will kill the O2 if it's leaded.
But, if you are running the car in the 1/4 then you are WOT and the car is not looking at the O2 for fuel adjustment because you are in open loop.

Do you have a fuel pump in the car? If not, you are probably running out of fuel since the stock pumps just plain suck.

 

is your check engine light on?

 

you need to check your cel code if you have one. I had a bad front 02 sensor at 43K miles but it was damaged during an 02 housing install.. yes this will make your car run like ****.. run rich as hell!.. take your plugs out, mine were black! your ecu will continue to attempt to richen the fuel without a signal from the 02 sensor. I suggest checking the code and fixing hte problem right away.. with the added fuel you are probably insanely rich and risk hurting the engine.

 

from what i am hearing it seems that it wouldnt be my o2 sensor, i have a walbro 255 pump sorry for not stating that, and my plugs seemed to be fine when i took them out to try replacing them, they were not black at all. also i have no cel but i do have the cel fix from perrin still wondering what this could be. any other suggestions will be appreciated

 

put a wideband on it..

 

Okay, not black at all means how whit and clean were they?
I am wondering 2 things. Are you sure it's not just the high heat and humidity and do you have any post Dynoflash mods?

 

i am positive that its not high heat and humidity, it has been chilly a few days here and its the same deal. also there were no post dynoflash modifications other than replacing my rvm ic piping with ams wich should make absolutely no difference at all