Okay, I managed to get the Service Engine light off, but today the Check Engine light came on. Read the codes with my newly aquired OBDII reader and I come back with P1314 and P1313, which I understand are for the Cat Converters. I reset the CEL and drove around for a bit, and the light has stayed off. My question is, should I just plan on replacing the cats? And do I need to replace the O2 sensors (or anything else) while I'm at it, even if I'm not getting any codes coming up for them?

Regards,
Joe Martin

P.S. It's a 98 Disco, with 179k (only 50k on the engine)

 

Both cats are showing their age and should be replaced sooner then later to allow you the best performance, how about your 02's are they original, if so they are way past needing to be replaced.

 

Magnaflow makes some good high flow replacements. I had some welded in instead of replacing with the $700 entire Y pipe. If your O2's are original, you are due. All 4 at the same time. The $$ you save on the cats will justify the O2's for your pocketbook. Magnaflow has a list of dealers if you don't have a muffler shop you are familiar with.

 

If I replaced the cats, and then the O2's at a later date (or vice versa), would it do more harm than good? Should I wait until I can do both at the same time?

Regards,
Joe Martin

 

When you replace the cats make sure they are the heavy metal versions.

 

P1313 and P1314 are misfire codes. It's recommended to change the o2 sensors at the same time when you replace the old cats. A bad o2 sensor will cause poor running conditions and ruin your new cats. And grussell is right, make sure you get the Heavy Metals.

 

Need to quote the fault codes correctly, they are misfire/cat damage fault codes for each bank, not related to a cylinder misfire or you would also have either or a 300 and a 1300 misfire code.
Change out your tired cats that were probably damaged by the original engine, possibily coolant contamination and replace the 02's which although they are not faulting, they are very limited as to the ability to set proper air fuel mixtures.