obdii, will it give codes w/o CEL on? (1 Viewer)

[Benson]

The truck in question is a '99 Tacoma with the 3.4 ltr engine. I am having problems with the engine stumbling and missing under load, particularly with hard acceleration. I've tried a number of different things to fix it without luck.

Question - will the obdii system throw off codes even though the check engine light is not on? It would be nice if I had something to help track down the problem - but the CEL is not on. Should I get a code reader and check it anyway or is that a waste of time?

Thanks in advance.

 

[LukeZero]

Yes OBD2 monitors many things, only some of which will cause the check engine light to show. You can buy your own scanner for something like $150-$200 or you can have it scanned by a mechanic or AutoZone, Advance, Checkers, Kragen, PepBoys, etc. When my 4Runner was stumbling and idling poorly, my mechanic buddy hooked his $10,000 Snap-On scanner to it and it said "#4 cylinder missing".

We checked and it was still there [not missing] so we figured it must be plug or wire, not coil because cylinders 3 & 4 share a coil. Changed plugs and wires, its been great since.

Hope this helps. Luke

 

[Benson]

Thanks.

I'll drop by Checker and borrow their scanner.