I'm just curious if I may be getting taken by a mechanic. For three years I had a check engine light on that was finally repaired last week. The FIXD message said it had something to do with the catalyst efficiency. The mechanic reported it needed a new catalytic converter. I had no way to disprove him. Unless is says Fisher Price on it I don't know what I'm doing under the hood. Well, $2K later it was repaired last Wednesday and I drove it home. I was happy that the check engine light was finally off. Until yesterday. Just two days after I drove it home the light popped back on. This time my FIXD message is the Knock Sensor. This will be another costly repair. Is it possible the mechanic could have done something to cause this? It seems suspicious to me.

03 Hummer H2 189K Code PO332 Knock Sensor, Major Driving Impact - Could cause damage to your vehicle with continued driving.

 

the knock sensor code was probably pending. codes get set in certain orders. sometimes you have to fix one issue to then get the next set of codes. you can try a different brand of gas.

 

 

he had it replaced already hummerz

now his issues are the knock sensors

 

Without receiving pertinent information, my synopsis: engine replacement.

 

Seriously? Wow! Other than the info in my post what additional do you need?

 

ok if its an 03 H2 like mine the knock sensors are located under the intake manifold. the knock sensors are prone to going bad as well as its harness and connector. it can be as simple as the harness connector needs cleaning or the sensors need replacement. bad gas can also trigger the code.

 

Thanks, bronxteck. Should I try premium gas before seeing a mechanic or do I not even have time for that?

 

you can try a higher octane gas but the truck is made to run on 87 the higher the octane the less nock should occur.... another thing that can cause knock is heavily carbonized pistons. but usually its just bad sensors or sensor harness
needs 2 sensors https://www.rockauto.com/en/catalog/hummer,2003,h2,6.0l+v8,1398562,exhaust+&+emission, knock+/+detonation+sensor,5108
​​​​​​needs 1 complete harness the 17$ one https://www.rockauto.com/en/catalog/...onnector,13326
you also might need new intake manifold gaskets if the ones there have never been replaced.
https://www.rockauto.com/en/catalog/...ld+gasket,5424
here is a video

 

Thanks for all the help, bronxteck.