PulpFriction

But did you change the oil? Good chance that's been neglected.

Fixing O2 sensor problems is pretty important, because your flexfuel car needs that data whether it's eating E85 or not.

P0455 is just the P0442 graduating from a small evap leak to a large one. It can be a pita to find, but going large should make it easier. There is a TSB on the subject, if you think a long list of places to look for the leak will be helpful. I mentioned a link to it in a recent post.

But there's a good chance it's a corroded evap line somewhere between the tank and mid-cabin, near the wheel in particular. The evap and fuel line run together. They both corrode at the clips and inside the little insulation blankets.

Any gas smell? If you see much corrosion, you could just replace both lines. They'll leak eventually. Replacement just from the tank to mid cabin often will suffice. Nylon lines are easiest. There's an "Inline Tube" brand kit. I no longer like it. Fit problems.

Once you replace the thermostat Donbrew mentioned, be sure to get all the air out of the cooling system.

C0040 could be just a loose wire or bad connector for the RF wheel speed sensor. Could be the cause of the other C code?

rose359

Have not changed oil yet; it appears clean on the dipstick and is full. I am hoping to get more done in the spring when Minnesota weather improves.

This evening, it was hard to start. It required quite a bit of cranking. It is always something. I am not sure about E85 fuel; this is the first vehicle I have had that is made for it.

rose359

1) The exhaust is loud. Could a bad O2 Sensor be causing the exhaust to be loud?
2) I looked at some YouTube videos on HHR 2.2 O2 sensors; they refer to upstream and downstream. Is #2 downstream?
Thanks

Oldblue

Upstream is closest to the engine , downstream is the 2nd towards the back after the catalytic converter

donbrew

1) NO, but might be the cause of some of the codes. Probably a cracked flex pipe. The accordion at the exhaust flange.
2) #1 is upstream , #2 is downstream

rose359

How difficult is it to repair or replace a cracked flex pipe?

donbrew

Just a matter of a few rusted bolts, there are several way to go. New catalytic converter, new flex welded, new flex clamped. If you pay someone to do it they are all about the same price. Easiest is a new cat/downpipe 5 bolts and 2 O2 sensors. Cats on eBay run about $100-$150, shop labor about an hour.

rose359

We are poised to receive 18-24 inches of snow Tuesday into Wednesday, followed by 40-50 MPH winds; I will have to get back to HHR work later.

Next I need to determine the source of the exhaust leak. On an older Chevy pickup, I had an O2 sensor leaking exhaust, but probably not this time.

Could the exhaust leak be causing the O2 sensor to not be working properly without itself being defective? Could the opening be adding some air to the exhaust mix? Thanks

donbrew

That is what we have been trying to say.

Oldblue

It could be flex pipe or it could be exhaust manifold cracked remove the heat shield and have a look.