early 95' 02 questions

[yellowjacket]

i just bought a 95gt that was made in january, and the guy i bought it from put an offroad h pipe on it and he said he removed the 02 sensors. i'm pretty sure i need to put em back on cuz it surges when cold, gets crappy mileage, and engine light will blink once in awhile when hiway driving.he didnt even change the headers either, i'm gonna put some equal length shorties on soon as we get a warm day here, which i've seen on here that it's a pain in the butt on these cars. have to lift the engine? that sux, but oh well. he also just bypassed the smog pump with a different belt but left it all there :dunno:anyways, i'd appreciate some opinions on what i should do. thanks

 

[ryclef331]

The surging when cold won't be caused by the lack of 02 sensors. The ECU ignores the O2 sensors until they are warmed up (called open loop mode). Open loop mode is when the ECU refers to a set table to run off of ignoring the sensors. It also uses open loop mode at WOT. By removing the O2 sensors, the ECU realizes it has no way to read the A/F so it refers itself to a known "safe" table and runs off of that. This same program is pig rich to be safe which explains your shitty mileage. People will yank their o2s and say their cars run noticibly better....its a band aid fix. Put the O2s back in it, perform the idle surge sticky at the top, and then report back. You may have a coolant sensor crapping on ya causing cold start issues but thats a cheap and easy fix.