I have a 2006 HHR 2.2L, just over 80,000 mi that is getting a code for a O2 upstream sensor faulting. I want to make sure I am looking at the right part here before I start. It doesn't appear easy to get to from top or bottom and the heat shield from the exhaust manifold looks to be in the way too. Any input would be appreciated.

 

If you are wanting to throw parts at it instead of finding out what is wrong, that's the correct area. Once you get the air filter housing and bracket off it's no that hard. There are tools made for the purpose.

 

Yes that's the upstream O2 sensor.

What code number do you have? There are codes for lean or rich condition and there are codes for the O2 heater.

 

The code being thrown is P0135. I have taken out fuse designated 33 and it cleared the CEL for a short time. The CEL returned after about 30 miles of driving. I pulled the fuse again and again the CEL went off.

 

Ok your code is saying that the heater side of the O2 sensor is not working properly.

In most cases it's a faulty O2 sensor heating element. The heater side of the O2 can easily be checked with an multi meter.

Also it can be as simple as a blown fuse for the O2 heating circuit.

 

X2 to Lucky's advice, a little diagnostic work before a trip to the auto parts store can save you some dough.

 

X3 on Lucky's advice!

 

Pulled and inspected fuse in slot 33. As my previous post stated, it cleared the CEL for about 30 miles before it returned. The fact that the code pulled indicates heater side O2 sensor and that pulling fuse 33 cleared the code briefly to me says, change the O2 sensor. A previous poster stated "once you get the air filter housing and bracket off it's no that hard". Is this correct for the '06 as well? I'm from from a novice working on vehicles. I have swapped transmissions, heads and done jobs that local shops said "they didn't feel comfortable" doing. It's getting to that stage with the HHR where a little wrenching is needed.

 

Then if you are comfortable that your tests have confirmed the failed part, yes change it.
I recommend the AC Delco part, some aftermarket parts don't respond to the ECM's expectations and can through codes, I would also recommend disconnect the negative cable at the battery to ensure no current surges while disconnecting the O2 sensor

 

One of these type wrenches should help.
O2 Oxygen Sensor Socket 3 8" Drive x 7 8" | eBay

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