Questions for those with a FEDERAL EMISSIONS 5th gen Maxima w/ Y-pipe...Please Reply:

(1) How long has it been on your car?

(2) Have you ever gotten a "Service Engine Soon" light?

(3) Did you ever pull the code to see the cause?
(By getting your car hooked up to a scanner)

(4) If you answered YES to #3...
What codes did you get? And how did you fix it?

The reason I am asking is because lately I have been getting the Service Engine Soon warning light...So I had the code pulled and it came up as follows:

P0135 O2 Sensor Heater Fault (Bank 1 Sensor 1)
P0141 O2 Sensor Heater Fault (Bank 1 Sensor 2)
P0155 O2 Sensor Heater Fault (Bank 2 Sensor 1)

Supposedly, this means that I have THREE (3) bad O2 sensors (out of four total sensors).
Which must be correct since my Air Fuel Ratio gauge is no longer functioning.
I've spoken to a few mechanics who say that they think the reason is because after adding my Y-pipe, which eliminates the pre-cats, my computer is getting bad readings because, on an OBDII vehicle, you HAVE TO HAVE a catalytic converter inbetween EACH O2 sensor (and the y-pipe eliminates two cats).
I really don't wanna have to put the stock "y" back on.

Lemme know if anyone has any solution/input.

Thank You In Advance.

PS: I've had the Y-pipe on my car for over 2 months now and have never had a problem...until this past week i finally modified the rest of my exhaust... 3" cat... 3" piping into a 3" resonator and 3" muffler...

 

Clear your ECM and see if the codes come back. It may be one o2 sensor at fault and it is screwing up the whole system? I don't have 5th gen but I had almost the same setup as you{2 1/2} and never had any o2 sensors act up, I am telling you this because my car also has OBDII{you may want to rule out your mechanics thoery}. Good luck with your car.

 

Check the O2 sensor fuse. The same thing happened to me and I checked the fuse and it was blown. i doubt all 3 of your o2 sensors went bad at the same time. But you never know. Hope this helps