Idle issue multiple error codes

[jjman]

I have a 97 Explorer that is giving a friend of mine grief. The engine is running fine then seems to slow and then catch up again. The accellerator is occasionally unresponsive then overly so. Went to the local autoparts store and had the error codes read. I got the following

P0153 and was told that the O2 sensor was bad (Bank 2 sensor)

1151 - gas mixture too lean i think
1152 - gas mixture too rich
was told the two of these together mean the air flow sensor is bad

and the notorious P0300 - 3rd spark plug missing he said.

Before i start throwing parts at this problem i want to know if any of you could shed some light on a possible solution that does not involve replacing the 02 sensor, the airflow sensor, and giving it a tune up again.

 

[CDW6212R]

Welcome, and make sure the tune-up stuff is good, those are just the easiest and cheapest things to start with. Which engine do you have, the SOHC tends to have upper intake gaskets to leak, which isn't expensive, mine is doing that now. The O2 sensors can be left in for a long time, but if they have 100k+ miles, then the fuel mileage gained from changing them can be worth it.
From what I've heard of if the MAF sensor goes out the engine runs very poorly, or not at all.


Look hard at all of the vacuum lines, and the whole EGR system. You can clean the IAC unit, sometimes that greatly improves an idle issue. Some CEL's point to other sensors like the DPFE sensor, also a common thing to go out after 5-10 years. Good luck,