Service Engine Soon light keeps coming on

[jeffgold79932]

Our 2000 I30's "service engine soon" light came on recently and I took it to my trusted independent mechanic. He ran diagnostics and determined that two ox sensors were bad. They were changed and the light came on again. We changed the last "front?" sensor and we drove off. Two days later the light is on again. First question: I've read about "knock sensors" are they the same as the "oxyegn sensors"? Now I'm about to call the mechanic and tell him the bad news that the light's on again. Any advice on where to look next? The car runs fine except for slight hesitation when it's cold, but only for the first time you accellerate. Thanks

[elwesso]

The knock sensors and the oxygen sensors are completely different......

The knock sensors are little things that are bolted to the block and they detect if detonation is occuring.....

I dont know if on the I's the CEL wil come on for knock sensors.... I know for the old Qs they dont.....

Welcome to NICO!!!!

EDIT: As far as your hesitation, the knock sensors would defintely have a key role in producing that.... I bet they are on their way out....

[Q451990]

I dont know if on the I's the CEL wil come on for knock sensors.... I know for the old Qs they dont.....

Any car after 1996 will have more "check engine" lights because of the switch to OBDII (more stringent emissions control requirements) - so I'd say that knock sensor would be on the list of things that would turn on the light.

I'd sure consider taking it to someone with a Nissan Consult, which will probably mean a dealership, either Nissan or Infinti.

How many miles are on your I30?

Heath

[NISTECH]

The knock sensor code to this day on nissan/infiniti's DOES NOT trigger the CEL. The 2000 maxima which is the same car except for the clock. has had some problems with the air flow meter. but also when you replaced the O2's did he do the reprogram of the ecm? ther is a bulliten on this condition with rear O2's which requires a reprogram of the ecm when replacing them.

[jeffgold79932]

Thanks for the help. My mechanic wants to make it right so I'm taking it back in the morning. From all your postings (here and on other threads)the knock sensor does not trip the SEL. The car has 55,000 miles on it FYI.Will let you know what codes come up next.

[Q451990]

The car has 55,000 miles on it FYI.

Didn't the car come with a 6yr/60k warranty??

Heath