Toyota Repair: 99 toyota camry CEL, air fuel ratio, air fuel mixture

Question

----Question-----
I have a 99 toyota camry ce 4 cyl 5 speed manual w/ 85,000 miles. Yesterday I put gas in the car and 3 hours later the CEL came on.  The next morning I took it to AutoZone and had the code read, it was a P1133.  They reset the code to see if it comes back.  Now just over two weeks later it came back on again with the same P1133 code.  I'm hoping this isn't the Air-Fuel Mixture sensor in the exhaust manifold again, because that's a $200+ item that I had to replace just last year, and at +$200 a pop I would hope they last longer than 1 year.  What do you think could have caused it to come on, and will it come back?  Any Help is greatly appreciated, Thanks.          George
         E-mail: Pooohdaddy@insightbb.com


Answer
Toyota had issued a service bulletin regarding this condition(EG004-01) it involves replacing the ECM, it has a warranty period of 8yrs/80,000 miles, it seems that you are about 5,000 miles over this mileage limit, if the toyota dealer replaced the sensor last year and the mileage was less than 80,000 miles you may have a course of action to take since they should have referred to this bulletin then, the problem is not the air/fuel ratio sensor, it's the ECM, if you would like I can mail a copy of the service bulletin to you but I will need an email address and ask that you keep the source anonymous when you contact the toyota dealer.