I think my cats are clogged but not sure...and I would hate to fix something that's not broken. I had a bad O2 sensor for a little bit but fixed now. No CEL now but it seems like the cat is clogged b/c I have oil dripping from it.



Now, I was under the impression that a clogged cat would send a CEL or am I wrong?

 

You shouldn't have oil dripping from it, even if it was clogged. That would mean there is considerable oil in your exhaust and your exhaust smoke would be heavily blue. If it's not somewhere obvious like the valve covers or spilled oil you may want to check your rear main seal. You won't be able to see it as it is where the crankshaft "exits" the block for the transmission but it would cause oil to leak out under the car. There should be a rectangular shaped rubber cover (inspection cover for the trans) that you can pop off, if there is oil up in there than you found your problem.

 

If the CAT is clogged it should flag a CEL. It would likely flag an issue with the post CAT O2 sensor b/c it would know your CAT is not functioning (doing its job)...

 

Thats what I figured (that a clogged cat would send a CEL). Didn't even think about the blue smoke.

And it better not be a rear main seal....I JUST had my cam cover, valve cover gasket, and front main seal replaced along with timing belt and water pump. Time to go dig the inspection cover!! UGH!!!

 

Rear main is often overlooked in maintenance because...it's just a serious beotch to get to. Not to mention expensive if done at a shop. Transmission has to be removed and moved out of the way to get to that seal.