Labree High-flow Cat Woes

[A4orce84]

Hey Everyone,

So me and a buddy installed my Labree HFC about a month ago, and after a few days it I started getting a "too rich" CEL and the car would stumble a bit if just idling (only when in park).

You can audibly hear a leak sound, the "pshh" of air, so I assumed it was the connection from HFC to the down pipe that was loose. I took it to an exhaust shop since I didn't want to deal with taking everything apart again (it took 6 hours to install the HFC originally) and would hope it would be an easy fix.

However, talking to the guy...he said that since the supposed "leak" was after my O2 sensors, it wouldn't be catching it to throw the code. He traced the leak to somewhere near the manifold so now I'm really clueless...

I thought I'd ask everyone who has installed a testpipe/HFC/replacement cat. converter for advice and what I need to look for and do to correct the problem. Thanks in advance everyone!

--Asif

[onemoremile]

The manifold is before the o2 sensors. Either something was lost in translation or the tech did you no favors.

My Labree HFC has been fine for years now. Are you sure it isn't a flange leaking? It should be really easy to pinpoint a leak. Put the car on a lift with the engine running. Blow cigarette smoke around the cat and exhaust system and look for smoke blowing away from it.

[A4orce84]

Well if it is BEFORE the O2 sensors, wouldn't that make sense? If there is a leak by the time it hits the O2 sensors on the cat, it would go off? It made sense in my head..

[onemoremile]

If it sets off a code it would have to be before the sensors. The contradiction is this line: "However, talking to the guy...he said that since the supposed "leak" was after my O2 sensors, it wouldn't be catching it to throw the code."

I'd take it somewhere else and have them find the leak. Or you could do the smoke trick in your garage. Cigars work even better since the smoke is usually thicker. Don't inhale it, just pull it into your mouth and blow it on the exhaust. The fans may move it a bit but you'll notice if there is a leak since it will be blowing in a funny direction in only one spot.

[Nebone]

Hopefully you used new gaskets and new copper lock nuts. When I installed mine (after hours of cursing) I was realllllly glad I had no leaks but I made sure everything was really tight in the first place.

[A4orce84]

Yeah I did, new gaskets and the labree came with new hardware

[mike-2ptzero]

If it sets off a code it would have to be before the sensors. The contradiction is this line: "However, talking to the guy...he said that since the supposed "leak" was after my O2 sensors, it wouldn't be catching it to throw the code."

I'd take it somewhere else and have them find the leak. Or you could do the smoke trick in your garage. Cigars work even better since the smoke is usually thicker. Don't inhale it, just pull it into your mouth and blow it on the exhaust. The fans may move it a bit but you'll notice if there is a leak since it will be blowing in a funny direction in only one spot.

I think the tech was saying that the supposed leak that the owner of the car was talking about was after the 02 so it wouldn't be the reason the 02 sensor was throwing a code and then ended up tracing another leak that was at the manifold which had nothing to do with the cat itself.

No reason to take it to another shop seeing that the first one already found a leak at the manifold which needs to be fixed if the first shop did not fix it for him.

[A4orce84]

Spot on Mike, thanks!

I'm not sure, the shop couldn't work on it more since it was near closing time. I'll probably take it back on Monday and see what they can do

[audiness]

check all your bolts too. The bolts on my turbo, cat, and manifold work themselves loose on a regular basis somehow

[A4orce84]

Hey Everyone,

As some of you may remember I was getting a CEL with the 17544 code, "running too lean", and I was talkin to my indy who pulled up some information that said it could be a bad MAF.

What kind of stumps me is that I got this same code when I had a hole in my OEM stock cat converter. however after ghetto rigging it so that it would work for a while the code disappeared.

Then I got a Labree High-flow cat to replace the OEM one, and the code comes and remains there. Just got done tightening everything, and that's when I talked to the indy to see if saw anything wrong.

He suggested replacing MAF, so I was just wondering if anyone could give me the low-down on what to look for with a dieing MAF? Thanks.




Also, onemoremile and other HFC kids:

Can you audibly here more "air" flowing now? I think with my OEM it was pretty much quiet around the stock cat converter/turbo area, but with the HFC I actually here more of a pshh sound than before....even now after tightening everything up.

[onemoremile]

I went from a gutted stock cat to a test pipe to a HFC. The test pipe was the loudest but the drone covered most of the spool whistle. The HFC does have the sound of rushing air but it isn't overdone.

[A4orce84]

Exactly, that's the sound I'm having! I think I just figured out my issue is with my Maf! yay!

Since you have to take off the airbox, maf, etc to install the HFC....I'm betting some dirt got in there during the install and after throwing everything back together....that's whats caused my CEL.


At least I hope, but it sounds like the logical problem!


-Asif

[audiness]

so how much cheaper are they compared to stasis ?

[A4orce84]

Hey Guys,

Thought I'd give the final update/conclusion to my CEL just in case for future reference.


So I ended up cleaning the MAF hoping/praying that was the issue. However I still had the lean-code CEL, and was starting to go crazy. I was poking around the engine area and found this:



I read on AW a busted check valve can make the car idle funny and possibly cause a CEL. So I got a new one and everything is back to normal! w00t!

I guess somewhere during the HFC install, the check-valve broke off. Either way, everything appears back to normal...and hopefully is.

Thanks everyone for putting up with my questions/whining! =)

--Asif

[Nebone]

How did you not notice that before?

[A4orce84]

It was just barely attached, I wiggled it around a bit to see if it was loose and it just came apart...