2001 Infinite I30. I had O2 Sensor Bank 1, Sensor 2 replaced in May of 2010 by a new mechanic. They recommended that, in these cars, all 4 sensors work together so ALL four should be replaced but I couldn't afford all, so I replace one and the "check engine" light went off. Light back on now. I took it to my old mechanic. The diag. code is coming up "middle catalytic converter". He says this should be replaced. I told my newer mechanic this. He says the failing O2 sensors are causing the CC to malfunction, hence the code and that I should replace all remaining sensors instead. Old mechanic says he detects no malfunctioning with remaining O2 sensors. Who's right? Help!
Is the problem the oxygen sensors or Catalytic converter? on 2001 Infiniti I30
by nestle57 in Richmond, VA on November 16, 2010
1 answer 1 comment
ANSWER by mastertech6371 on November 16, 2010
your old mechanic. you can test the o2 with a scanner and a scope for operation. you do not need to replace all when one fails, just the failed part. your shop can do a graph of the cat to see if it is bad or not. cats are common for failure from either age, 100k or more, or from misffires from a bad plug or coil over an extended period of time. Roy
COMMENT by nestle57 on November 16, 2010
My old mechanic comes through once more....Thanks for your help Mastertech!
Oxygen sensors (3) replaced to correct rough engine performance. Mass air flow sensor also checked. Now the engine will race on its own several times in a short trip.
I recently had o2 sensors code and got that taken care off i put 3 new o2 sensors in then i got the dreaded po420 code i replaced the middle catalytic converter which i heard was the right one then...