How to tell if O2s are bad?

[madonionrs]

The check engine is Not Lit (however it did go off a few days ago for a second)

Car is running good, however it is getting terrible milage and the exaust smells.

I don't want to spend $100 if I don't have to.

 

[LX302]

Scan for codes first before you spend any money.
A good tuneup always helps as well.

 

[madonionrs]

Yeah, I just replaced the plugs, the wires might be old (I doubt that would cause bad gas milage though) the cap and roder were done last spring (less than 3,000 miles ago.)

I'll have to check the codes... I assume it could have codes even if the check engine light is off, right?

I probably doesn't help that the prior owner put Long Tubes on and moved the O2s and just spliced the cords to make them longer.

 

[LX302]

Ok, if the CEL blipped on and then off, you most probably have a stored code in the EEC.