I have a real problem with my headers: Last week I had my Headers installed and my check engine ligth flashed a little bit, ok I was told it might do that, ok no prob. Now my check engine light stays on, and my trac off light flashs but wait thats not all my car is hesitating and won't go until I pop the clutch to 4-5 rpms. I had my car diagnosed today and I found out engine is burning 2 rich(I'm not sure what that means) and 3 of my cylinders are miss firing(I know what that means I just don't know y). I spoke with the lexus tech that only works on my cars and he told if I bring it in as is they will void my warranty, and he told me if I had put certain low octane gas in my car(Mobil, Exxon) its been know to mess with the injectors so he said I could try injector cleaner and Sunoco ultra 94 and that might help, but it helped for a while and now 6 hours later it is hesitating again. I NEED HELP, SOMEBODY'S HELP, ANYBODY'S HELP.

 

1. Installing headers won't, and can't, void your warranty UNLESS the headers themselves cause damage. That's federal law, and no matter how good a mechanic your tech is, he doesn't know squat about warranty law.

2. Your headers may be responsible for the engine running too rich, although usually the reverse is true. Running 2 rich, btw, means that too much gas is being injected relative to the amount of air. Too much fuel relative to air = rich. Too little = lean.

Did whoever did the install reconnect the Oxygen sensor? (Do your headers have a mounting for the OS?) W/o the OS, the engine computer will be hopelessly confused. Were any other changes made to the car at the same time?

3. Now that I think about it, your tech is an idiot. If the fuel injectors were plugged, the car would be running lean, not rich (less fuel = lean, remember?) Injector cleaner probably helped a bit because it leans out the air/fuel mixture a little. Oh, and all name brand fuels, including Mobil and Exxon, meet international standards for detergent levels.

4. A low octane gas will reduce power and gas mileage, but shouldn't cause a miss. The IS engine has a knock sensor (as do virtually all new car engines). IF you run on a lower octane fuel, the knock sensor will direct the computer to retard your engine's ignition timing to prevent serious knocking & pinging. Run a real low octane fuel and you'll get knocking, which can damage your engine, but that't not the same as missing.

I suspect the oxygen sensor's not connected, or not connected properly, isn't installed at all, or was damaged. The check engine light generally is caused by an emission system fault, and that fits with an OS problem. And running rich is probably the computer's fail safe position, to ensure the engine isn't damaged by running too lean.

I'd go back to the guy that installed your headers and ask him to check out the Oxygen Sensor.

 

You seem to know your sh%t do you have a aol instant messenger screen name???? I had the car hooked to a diagnostic machine today and the guy told me it was running 2 rich. I really would like to pick your brain hit me up later dude thnx 4 the info!!!!!

 

when the check engine light is on, it adds more fuel and causes the car to run rich because it goes into a "safe" mode.. u will loose most HP than u gained from these headers if ur check light stays on. As for the misfire im not sure what it could be.

 

Thanks 4 the help everybody but the problem is fixed, Turns out the O2 sensor was hooked up wrong, but now fixed and runnin like Preist to a little boy(LOL) Later again thanks everybody!!!!

 

Was it you Ferrari Who was looking for shocks for your IS?