I checked my engine codes after the engine light came on. They were P0133 and another indicating an A/F upstream sensor problem. I had it replaced by an independent mechanic. A few days after I had the same code. Mechanic went over it and thought it was loose wiring. A few days after codes P0133 and P0128 were generated. Now the light will come on every few days, will stay off for a few. Do I have to get my computer upgraded?
It would be nice to know what the “other” code was when you first read them.
Did anyone check for exhaust leaks? Vacuum/intake leaks? Clean the MAF sensor?
Or was that part just thrown in there? Those codes don’t tell you that parts are bad.
At the moment I would start by chasing the P0128. This is a pretty good write-up: http://www.obd-codes.com/p0128 Note that it says its intent is to detect a faulty thermostat - but that there’s a lot that goes into the computer figuring out whether the car takes too long to get up to temperature, and getting up to temp is about more than just the thermostat. So someone’s got some troubleshooting to do before another part gets tossed into the car.
The other code was A0…something. The mechanic did check for exhaust leaks and did know about vacuum leaks. He did not find any.