I HAVE A 90 HB SI THE MIL LIGHT IS ON I PULLED OUT THE CODE AND SAID O2 SENSOR SO I WENT TO KRAGEN AND BOUGHT THE OEM STYLE ONE SO I INSTALLED IT I RESET THE MIL LIGHT AND AFTER LIKE 10 MILES OF DRIVING IT IT TURNS BACK ON.......... EVERY TIME I TURN THE CAR OFF AND THEN BACK ON THE MIL LIGHT GOES OFF AND THE CAR RUNS LIKE A CHAMP BUT AFTER THOSE 10 MILES THE MIL LIGHT COMES BACK ON AND THE CAR RUNS REALLY BAD IT ACTS UP WEIRD AT LOW RPMS THE CAR HESITATES AND WHEN IT HITS AT 4500 RPMS IT PULLS REALLY HARD AND I THOUGHT IT WAS THE TPS SENSOR BUT I REPLACED IT ALREDY, I ALSO REPLACED THE FUEL FILTER AND ALSO IF U PUT THE GAS PEDAL DOWN FURTHER TO ACCELERATE IT TAKES A REALLY LONG TIME TO ACCELERATE AND THE CAR IS ALSO WAISTING GAS LIKE CRAZY IN THE LAST MONTH I PUT 400 MILES INTO IT AND HAD TO FILL UP THE GAS TANK LIKE 4 TIMES SO IF ANYONE CAN HELP ME THAT WOULD BE GREAT ESPECIALLY WITH THESE GAS PRICES

 

Just b/c you put everything in caps doesn't mean that we will help you faster, in fact, some might be put off by it.
About your problem, what is the exact code that your engine is throwing?

 

Dude......mines doing the same ****....dad thinks I broke the car after painting the valve cover..

When I rev it, it sounds like ****, like its missfiring like crazy. It sounds more like a motorcycle then a car. When driving around after 3500 RPM it doesn't accelerate well at all, takes FOREVER to get the MPH's higher. I know I need to replace the Speed and Oxygen Sensors. Any ideas? Similar problem.

 

man if that car has a heat sensor it might be bad if it is the car will still think its cold and feed more gas then nessasary and cause the car to suck after a little bit tha tis just a little bit of advice i don't know if that is what wrong but a possibility

 

IF you guys have MIL or Check Engine lights, you need to find the code. We can start guessing which sensor is bad all day, but that won't really get you anywhere. There are over 400 codes that could cause your MIL/ Check Engine light to go on. You could change the O2 sensor and that MIGHT fix the problem. But what if you change the O2 and its still doesn't work? You've just wasted $100+ and your still doesn't work but if you had pulled the code and did some diagnosing, you would have fixed what was broken the first time and saved some money.

 

thats what he did^^^^ and after ten minutes of driving the code comes back and the MIL light comes back on until he turns the car off

 

Just try MIL Eliminators. $25 each.

 

Sorry to bring up and old topic, I figured out what was wrong with my car(took it to a mechanic, me = noob) it was the FUSE, and the FUSE BOX HARNESS. New fuse's kept blowing after driving it for around 10 minutes, so it's a short somewhere in the Fuse box harness. So if your CEL Code pulls up as Both O2's and the Speedo, then it's most likely the fuse going out. Hope that helps!