No, George, I have not jacked up the car and crawled under it with engine running. I have inspected as best I can and don't see anything obvious. The exhaust "rumble" is coming from front of firewall from best detection I can muster. Looking down on flex pipe I don't see any cracks or leak sources but the sound is coming from that area, not under the car.
BTW, I don't know why or how GM found me with a postcard advising me of the recall on ignition so late after the recall apparently took place. I bought this car from a used car dealer about 1 year ago. How GM found out I even own it I don't know.
I utilize forums like this obviously because probably like most folks on here we prefer to diy as much as possible either out of desire to maintain own cars or necessity to avoid financial hit of professional help. I'm both of those.
I appreciate the help of HHR owners who have been there done that.

 

You need to cut, fit, reinstall, tack weld. Than you can take it back off the car and weld it.

Here is a how-to https://www.chevyhhr.net/forums/how-...ex-pipe-31536/

 

The DMV knows your name, address and vehicle VIN. I'm still getting notices about the recall on a 2008 that went to the crusher in 2012.

The flex pipe usually cracks on the bottom side

 

I posted previously about my louder than normal exhaust which seems to be coming from in the engine bay, at rear of engine. Others quickly replied that it was almost a certainty to be the flex pipe. Some suggested just replacing the flex pipe and cat as one piece and be done with it. BUT.... I'm in California and I am noticing that the expense of a California compliant cat is A LOT HIGHER than the typical units being sold on ebay for $120ish. In the interest of economics, I'm prepared to take the risk that cat is ok and just need flex pipe, but I know this is a job that will require welding services. Still cheaper.
My new question is this......all of the flex pipes I'm seeing on ebay for $35 or so, look like the flex part is a stainless mesh. On my car, what I would call the flex part looks more like an accordian. Is the mesh type just the better, newer design, or is this also something California related?

 

The mesh makes for better flex, less likely to fail again. No functional difference.

You don't HAVE to weld it on, it is possible to use a clamp for a DIY job. I would get either one with a bend in it or the ones that have the bend and extend all the way to the cat.

 

My 09(CA) has the mesh, my guess is that the accordian is in there, and the mesh is for structural strength.

I'm going to merge this with your other thread.

 

Folks....this actually goes to an existing thread I have on my 2009 2.2 HHR in CALIFORNIA,but I can't find the thread. Hoping for more help.
I have an 0420. I had a cracked flex pipe AND exhaust manifold, both of which were replaced in hope that it would clear the 0420. It did not.
0420 is still setting, so now I'm guessing I need to replace the cats (dual on this car).
Problem......I really can't afford a California CARB compliant cat as found all over the web for average price of $800 for a direct fit assembly that includes a flex pipe that I have just replaced. So far I have spent $175 for the flex pipe and welder to cut in the new one, plus now $282 for a new manifold and installation labor. So roughly $450 so far and still 0420.

Can anyone suggest THE MOST INEXPENSIVE approach at this point to replace the cat(s)? I am looking specifically for source, part number or description and price for just the 2 cat(s) that are CARB compliant that I would then take to the muffler shop to have welded in.

I appreciate any help on this, being on a shoestring budget here.

 

Captron - your latest NEW thread merged YET again.

Its so easy to find your posts/threads - just click on your name in the upper right corner and select "MY POSTS".

 

I suggest you go to a muffler shop and ask them. They may be able to cut and weld a replacement in. The only one that matters is the first one, the second is mostly window dressing and is not monitored by the OBD2.

Or, look on eBay, this one is $452. 5 bolts, 2 sensors.
https://www.ebay.com/itm/Catalytic-C...LH_TitleDesc=0

This is a weld in
https://www.ebay.com/itm/California-...LH_TitleDesc=0

 

Wow, good find on the Magnaflow!!