I have a CEL on all the time cuz of no cat. When driving on vacation last week I was getting back on the highway and was in boost and my CEL blinked a few times. I let off the gas and slowed down but everything seemed to be fine so I continued to drive for the next 4hrs with no problems. A couple days later I stopped at an Advanced Auto Parts and had them read my CEL. Here's what it said...

DTC (Codes)

P0420
Catalyst Efficiency
Below Threshold
(Bank 1)

DTC Pending (Codes)

P0300
Random/Multiple
Cylinder
Misfire Detected

P0301
Cylinder 1
Misfire Detected

P0304
Cylinder 4
Misfire Detected

P0420
Catalyst Efficiency
Below Threshold
(Bank 1)

What does this mean? Is something wrong, need to be checked, or need to be replaced? I did have the CEL read about a week before I left for vacation and everything was fine except for the cat. Any thoughts?

 

re-gap plugs... i have mine set at 26 when bought they were at 35. your problem sounds like what my friend with a boosted spec-v had when he got a greddy turbo kit the tune need to pull more timing, well thats what the tuner said

 

When re-gapping is it just keep changing it until right or should I just set it to 26 or another set number?

 

um start at like 28 i wouldn't go much more then 25

 

Well I havent had this problem on my Turbo tC but last week on my beater car I got the same codes. Turned out to be alittle water got in my gas tank. I'm not telling you should try this but a bottle of HEET took care of that problem.

 

This is interesting. I was getting back on the highway from getting gas after I suspect the problem happened. I think I'll go to auto zone tomorrow and make sure the codes were cleared and go back once a week to check. If it happens again I'll re-gap the plugs.

 

watching

 

watching