knhinc

The service engine light is always on. The car has custom header's and well every year we have the problem with getting it to pass smog because the light is always on. A few different sensors went out a couple of years ago and we replaced them, but every time we get it fixed and then pass smog, within a few days the light is coming back on. A friend of mine told me just today that they make sensors that i can replace with the actual sensors that are like dummy sensors or trick sensors or something like that, that will tell the cars computer that all is well. Is there such a thing and if so where can i get them? I'm no mechanic by all means but i do know some stuff about cars and motors. I took auto mechanics at school for 3 years. I guess with that said, i will do whatever i can to fix my cars myself before taking it to a shop. I'm also new to this website and forum.
Thanks for any input.
Kevin

moparman

Need to know what kind of car, year, engine etc. First thing is to put a scan tool on it to see what is going on.

Injuneer

The only "trick" sensors are "O2 sims" that replace the after-cat O2 sensors. The after-cat sensors are only used in OBD-II, and only used to determine if the catalytic converters are there and working.

But, as noted, without knowing basic info about your car - year, model, engine, trans and any major mods, it's impossible to help you.