I have a 2004 Nissan Frontier pickup that I bought used in 2012. Shortly after I purchased it the the check engine light came on, would go off and back on. Last year (before inspection) I hooked it to the diagnostic auto scanner and it read the error as four oxygen sensors. The truck was running fine but in order to get it inspected I ended up changing all four sensors. The light came back on within the week (as soon as it rained) then would go off a few days later. Rain–on, then off. I managed to get it in for inspection on one of the days the light was off. So, now it is again inspection time. Light is on, still error on the scanner as oxygen sensors. Light has not gone off in a long time.
Also noting here that I have checked this error on several different scanners. I am not spending $800 again when I really don’t think this is the problem. The truck is running fine.
Before I take it to the dealership is there anything else this could be? Thanks for any help!
I’m wondering if you have a contamination issue since all four sensors seem to be affected. Sensors can be contaminated by antifreeze from a blown head gasket or RTV used in a rebuild. Has the truck been using coolant?
If not contamination, I would also check to see if there are any TSBs (tech service bulletins) on this issue. Has Nissan issued new software for the PCM? If so it could be as simple as reflashing the PCM software.
thanks for all this good info–I will check all of it out. The diagnostic codes are:P1148, P0132, P0152, P0158 & P0138. I will look further into the TSB mentioned above also. I will keep you posted on the outcome–thanks again!
Hopefully the TSB fix is the problem. If not, what’s happening is the engine computer (ECM) is having difficulty setting the correct air to fuel ratio. It measures the air flow into the engine and then calculates the amount of gas to inject. When it does this, it is supposed to cause all of the gas and all of the air to be burned in the cylinder. When the O2 sensor says either some air remains, or some fuel remains, that confuses the ECM, and the ECM blames it on the O2 sensors b/c it discovered the problem reading the O2 sensors. The ECM is blaming the messenger in other words. O2 sensor codes usually aren’t caused by faulty O2 sensors, instead the cause is more likely to be air leaks, EGR problems, PCV problems, problematic fuel injectors, faulty air flow sensors, etc.
Edit: You can type P1148 into the Google search bar for add’l info.
Thank you all for the great suggestions about the TSB and the ground wire. Fixed the problem for a few bucks. Light OFF and passed inspection! I owe you one!