Hi I have a 350z the engine light came on it was the o2 censor had it replaced and it just keeps coming on the code reads the same every time any advice please

SOURCE: Check engine light on; used

Run fuel system cleaner through it, you have dirty injectors is all!!

SOURCE: Check Engine Light

It sounds like you may have a failing Mass Air Flow sensor, seems like Ive been seeing these tied together quite often. Its a little tricky but a good repair shop should be able to test this sensor. I dont want to tell you to replace it without having it tested cause they are a bit pricey but check around, you never know. Hope this give youu another idea where to look.

SOURCE: check engine light

I would say that your o2 sensors are faulty either the pre or the post . They must be intermitten so I would replace both

SOURCE: Check Engine Light - P2181

Hi,first thing your cambelt and tensioner should have been replaced 13k miles ago,it would pay you to replace the water pump at the same time as they are known for impellor failure = cooling system fault=P2181 code,hope this helps.
Darren

ZJ Limited

• 17989 Answers
• Posted on Aug 28, 2012

SOURCE: why the codes po125 & po135 &po155 keep coming back?

Hi there:

DTC P0125 - Insufficient Coolant Temperature For Closed Loop Fuel Control

The simplest thing to do is to reset the code and see if it comes back.
If the code comes back, the problem is likely going to be the result of the above causes (faulty thermostat, faulty ECT sensor, or a low coolant level).


DTC P0135 - Oxygen O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)
or
DTC P0155 - 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)

A code P0135 and P0155 may mean that one or more of the following has happened:

• O2 Heater element resistance is high
• Internal short or open in the heater element
• O2 heater circuit wiring high resistance
• open or short to ground in the wiring harness