Not long after I put my new magnflow cat back on, my O2 censor went. So I put a new high flow cat on and a new sensor. When my engine light was on I noticed a good bit of carbon on my tip and bumper. Now, after I replaced the sensor and everything, I still have a good bit of carbon on my tip. My car does have a lotta miles on it...200,000+ But runs so damn good! It has had a tune up fairly recently. So do you guys have any suggestions?

 

a valve adjustment might help.