Hi guys,

since last year my 03 Maxima is running rich as hell. I have an EVAP CEL. My car is smelling gas a lot from the exhaust. I have Cattman headers, y pipe ... NWP spacers, i already cleaned my TB, new spark plug, CAI... I need help to solve this ! thx

 

You need a tune.

 

Fix the SES. Check for more SES. My car smells like gas sometimes and it's not running rich.

 

dyno or buy a wideband to be certain... bad injectors can cause the "gas" smell

 

Post1
Post2 or
Post3

ALL OF THE ABOVE.....

 

rich condition can be cause by A) too much air in the system and the ECU is trying to compensate by dumping fuel or B) your oxygen sensor(s) are or have taken a dump and are not sending correct voltage signal to the ECU.

The ECU uses the inputs from your upstream oxygen sensor to determine pulse width in your injectors, if it sees an incorrect voltage signal it will leave the injectors open longer thus adding more fuel .

The ECU has no idea if the oxygen sensors are bad ( other than a CEL when it sees an incorrect signal ) it will take the info it gets from the oxygen sensor and either add or remove fuel.

It would be cool if the ECU knew the sensors were bad and then ignore them, but it doesn't .

 

tune ittttttttt!

 

Allright ! Thx guyz ! I scanned the Max again and found a O2 sensor code ! So I'll get a O2 dual sim and things should be OK ! I also really want to tune it and advance timing but from what I read, it's pretty expensive .... I'll need a GReddy, wideband ....

 

Which O2 sensor was it?

 

Rear O2 sensor

 

Then that's probably not your problem. Front O2's control closed loop (MAF does the open loop), rears are back-ups to the fronts (in case the fronts go out of their range, the rears take over as primaries) and also the secondaries are said to monitor precat function.

 

Ok !! Thx a lot ! But I still not have any solution ! :P exept for a complete tune with e-manage !

 

Get the spark plug antifouler first, cheap fix ($5) and they are locally available at any auto parts store.

 

First things first, verify you're running rich, quantitatively, not qualitatively. So do what Hustle said.

 

Yeah I got the full Cattman and I was only smelling it dumping fuel on the freeway when I would get up on it after install but now nothing, I need to get up on a dyno also...soon very soon...