$7E8 and/or $7EA Trouble Codes
 

Here is some useful information for anyone experiencing a buzzing sound similar to engine knock under heavy acceleration, and for those who have gotten a $7E8 and/or $7EA Error Code. While the $7E8 EC COULD mean a cat failure, in my case, I believe the code was caused by a crack in the flex section of the exhaust pipe which is attached to the exhaust manifold. (see pic I'll post as soon as I figure out how to do that - it's been some time since I did that)



Here is the problem this causes the HHR owner:

(1) The front portion of the two piece exhaust pipe includes the flex section, the cat and one muffler type device, all as one part.

(2) The idiots in Sacramento have given the Dealers a seven year monopoly on cats, meaning I can't buy an aftermarket piece until 2015, even though my HHR has over 125,000 miles on it, which puts it way beyond the mandated eight year/80,000 mile warranty for such parts.

(3) Result is an installed price of $800 - $900 even using an indie muffler shop instead of dealer shop.

(4) The repair part I found from Bear River Converters cost $52 with shipping and is a FAR FAR stronger design than the original GM concept.
They are at http://www.bearriverconverters.com/
The Part # FX2061Set (includes the gasket)
You can also find this part on ebay by searching for "flex pipe"

Tomorrow the HHR goes to a local muffler shop that does a lot of custom work for installation. I'll update this posting with the labor cost for doing that.

Trying to add a pic to this thread
 

To attach a file to your post, you need to be using the main 'New Post' or 'New Thread' page and not 'Quick Reply'. To use the main 'New Post' page, click the 'Post Reply' button in the relevant thread.

On this page, below the message box, you will find a button labelled 'Manage Attachments'. Clicking this button will open a new window for uploading attachments. You can upload an attachment either from your computer or from another URL by using the appropriate box on this page. Alternatively you can click the Attachment Icon to open this page.

To upload a file from your computer, click the 'Browse' button and locate the file. To upload a file from another URL, enter the full URL for the file in the second box on this page. Once you have completed one of the boxes, click 'Upload'.

I can't find any sort of attachment button - can anyone help with this issue so I can post the pic? THX:thumb:

Follow these instructions...

Adding pics to a post

If the cat is still ok - check out the flex pipe replacement - http://www.bearriverconverters.com/I...2-b13369a605f3

$7E8 & $7EA Code Causes Picture
 

OK, here's the pic of the broken flex pipe and the repair part:
(And MANY THX to Greybeard for pointing me to the posting procedure. I've captured it for future reference)

https://www.chevyhhr.net/gallery/fil...RepairPipe.JPG

Ok, I give. What's with the "$" sign in these codes you're talking about? Did I miss something?

$ Sign in Error Codes
 

All I know is that is exactly what was displayed on the scanner screen ($7E8 and $7EA)

Appears to be a non-standard code, but my research indicates it implies a CAT failure. I believe the failure indication was due to the exhaust leaking from the broken flex pipe - I think my CAT is just fine.

Scratching my head too there George.

The only thing I've been able to come up with is that codes are displayed that way with an Autel Maxiscan code reader.

But what they translate into as far as the usual "P" codes is eluding me at the moment.

$7E8 & $7EA Error Codes
 

843de and ALL:

Correct in that my scanner is, as D43de assumes, an AUTEL unit bought from Harbor Freight.

Some of the results from my research:

http://answers.yahoo.com/question/in...9184543AAECrlg

http://www.fixya.com/cars/t6720274-e...ode_7e8_engine

So what that distills down to is the $xxx codes are "generic" and have other ECs behind them, which wasn't obvious at first.

Drilling past the $7E8, I found:

P0030 could indicate any of:
Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit open shorted to ground
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit poor electrical connection
- Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit fuse
- Faulty Engine Control Module (ECM)


and

P0053 could indicate any of:
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit open shorted to ground
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit poor electrical connection
- Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit fuse
- Faulty Engine Control Module (ECM)

From:
http://engine-codes.com/p0030.html
and
http://engine-codes.com/p0053.html

I've hi-lited the causes that are closest to the descriptions on this site.

I think it's reasonable to conclude that if a bunch of the hot exhaust at the manifold is escaping through a cracked flex pipe, then the O2 Sensor will not be reporting things as it should due to the lower volume of exhaust flowing past it.

(Besides that, the crack in the flex pipe was visible from below.)

That clears things up a bit, I wonder why AUTEL has to intentionally make things so obtuse.

I'd scoot your HHR to an auto parts store to cross check the codes against the AUTEL unit, just as insurance.