learnedOnHHR

Hi everyone,

This question is for a 2007 HHR LT 2.4L (Auto). For a flex pipe developing cracks, would it be better to weld in a replacement or replace the converter altogether? If the latter, could there be complications with reusing the existing O2 sensor? It would be my first time doing exhaust work, but it seems like the cat is accessible enough.

I got a quote from Midas for the welding route- $400. Almost the same price as if I bought the cat and had them, or another shop, put it in. I was looking at the Walker 54579 and Eastern 50374 on RockAuto. Does anyone have experience with either part?

Thanks for your help.

Oldblue

Welcome to the site, when my flexpipe cracked, I just replaced the whole thing, like the Walker part. eBay had a less expensive piece but that was back in 2013.
I did reuse the O2 sensors with no issues.
I figured the cost of welding in a patch was almost as much as replacing the whole pipe!
5 fasteners and the 2 sensors and your done!

donbrew

Welcome!

Change the sensor, avoid Bosch brand. $400 is excessive for the repair, it should not be more than 1.5 hours labor (more like .75), you can get the part from eBay vendors for around $65.

Last time I did it I took the pipe off and took it to a welder, it's only 5 rusted nuts, that should be replaced anyway. Part $65 labor $35, 2 bloody knuckles.

If you can get an OEM cat installed for $400 you're getting a real bargain! I would not get one except from GM. They will last forever, after-market not so much.

Oldblue

If the O2 sensors are ok, why replace?
I've had no issues with the $147.00 pipe in 3 years but the decision is yours,
It came with three new nuts and gasket for the exhaust manifold flange , and 2 nuts and bolts and gasket for the flange at the other end of the pipe.

This might not last as long as OEM , but the OEM is broken and requires replacement

http://m.ebay.com/itm/2006-2007-2008-2009-2010-2011-Chevrolet-HHR-exhaust-catalytic-converter-2-4L-/112035205134?nav=SEARCH

This clamps on with a new O2 bung, and is much more cost effective, and saves you the labour and welders fees


http://m.ebay.com/itm/2006-2007-2008-2009-Chevrolet-HHR-2-2L-and-2-4L-catalytic-converter-flex-repair-/111789658736?nav=SEARCH

donbrew

A. I was talking about the catalyst not being as good as OEM. The OEM catalyst doesn't seem to wear out with normal use. After Market is not the same quality, and many won't do the job correctly.

B. If you remove a sensor you might as well do what the manual says and replace it with new. They have "crush" washers and special sealant for the threads (it looks like anti-seize). If you are going to be arc welding the pipe you would be smart to remove the sensors. If you are replacing the entire pipe you gotta transfer them, at least.

Oldblue

Ah, that's very sound and sage reasoning, and to the OP, there you have it verious reasons as to your options, and why yes you should do things a certain way!
Thanks Don. I'm going with your advice the next time the flexpipe fails.

solman98

I did like oldblue and purchased an aftermarket off ebay. Might not last as long as the original, but then again the oem died just after 80K miles, so I could have bought 3-4 of those for the cost of an OEM and I put 40K miles on it before the accident and no issues, I also have emission testing.

learnedOnHHR

Thanks for the input. If I replace the converter, should I replace both O2 sensors, or just downstream?

Oldblue

Both

donbrew

"should", yes the book says to replace both. There are good reasons to.

Do I? That is a different question.

Please avoid Bosch, they usually cause problems, some people are lucky.

I found that the "generic" ones that you just splice the wiring are actually OK, maybe I was lucky.