ok so took my maxima through emissions the other day and it failed 3 of the 4 tests they run, so i put a gallon of alcohol in it and ran it through the next day, it passed on everything but the hydrocarbons at cruise, i just ordered a new o2 sensor and cat, what else should i look into to try and solve this?

 

Pull codes, you might be running excessively rich. O2 sensors are the first thing to replace, CHTS maybe the next.

S

 

oh geeze

i gotta do this this month too.....last time though....for ever

 

if im not getting a check engine light would there be a code to pull? and what is a chts.

 

There isn't a check engine light unless it's Cali spec. You'll need to pull the ecu out and pull codes. CHTS= Cylinder Head Temperature Sensor.

S

 

If you dont know where the ECU is, it is underneath the Passenger side Seat. Unscrew the seat and pull it out, dont forget to disconnect the power seat motor either. Take the cover off of the ECU and unscrew the ecu from the body of the car so you can move it around. Once you can see the green and red lights, there is a screw driver shaped ***, turn it clockwise gently until it stops. The light should blink Once for mode I, then twice for mode II, then three times for mode III, then four for mode VI and last it will blink five times for mode V if you go that far. Mode III (three) is the one you want to be in. That is the self diagnostic mode. So, what you will do is turn the ignition key to the acc position but not on. Turn the *** clockwise until it stops wait until the light blinks in a sequence of three times, once you see that it has blinked three times turn the *** counter clockwise then you will be in mode III (the self diagnostic mode). From there get ready to read the lights. There is a red light to the left and a green one to the right. Copy down how many times each one blinks and see what you find out when you look up the codes. Reseting is a sinch, after you are done turning the key to the off position, it automatically resets the ecu back to its regular settings. So, when you crank it up again it will be fine.

P.S. Make sure the car is warm and at operating temp when doing this.