My Tacoma seems to be running fine with no apparent issues but the CEL came on so I took it to both Autozone, then to Oreily for reading codes. Both places showed only one code: P0402. I took it to my Toyota dealer, they had codes P0100,P0110, and P0402. They reset CEL and insisted that if light comes back on then the MAF sensor ($1100) needs replaced. After about 80 miles it came back on. I decided to try cleaning the MAF sensor and reset CEL. Again, it came back on. I've heard that by disconnecting the MAF sensor while the engine is running and the engine shuts off, then the MAF sensor is ok, and doesn't need replaced. Is this true? I did this and my engine DOES shuts off immediately after disconnecting MAF sensor. I've also heard that a P0402 code usually means that the EGR valve is stuck open and the dpfe sensor is probably faulty and to test that first. I would hate to replace the expensive MAF sensor, only to find out the problem lies elsewhere. Any suggestions?
How long has your 2001 Toyota Tacoma had this problem?
RepairPal Certified shops can diagnose and repair your 2001 Toyota Tacoma. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
What you read about disconnecting a mass air while running is not always correct and can't be used as a method of diagnosing a MAF. If you are only getting the egr code back now I wouldn't just at replacing the MAF either. This could be an egr issue. I don't recommend guessing here. Bring it to a good independent shop and get it looked at again.
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Alex
