Greetings,
I have a 2003 LS series Trailblazer 4WD with a 4.2L engine. It has
44,000 miles on it, so far it only needed one part, still under warranty, the engine... Well, It has been a year since the engine was replaced, going to work the other day the check engine light came on. I took it to advance auto parts and they put it on the machine to get the error codes out of it. It came up with error code P0172, System Too Rich. I pulled the old one out and checked it for continituity, it is a 4 wire unit, the heater checked OK and then I put a volt meter across the sensor lines and heated it up a little with a propane torch, it never read over .065 volts. I thought it might be the O2 sensor, so, I picked one up. They gave me a Bosch 15285. I took out the old one and when I was putting in the new one I noticed that it didn't have any slits on the side like the original. I tried it in the opening and it fit, so, I put it in. Well, the next day the check engine came on. I thought the the computer module may need cleared so I disconnected the battery for half an hour or so and hooked up the battery, Check engine light came on after 20 or so miles. I know that it may be something else. I had the check engine come on one time because the gas cap was loose. My question would be is the Bosch 15285 the proper sensor for the upstream sensor? Is there any cheap error reading units out there on the market?As always, Thanks in advance,
Markus