Wes Garland

Hey, folks --

I have a bad bank 2 cat and need to get my van legal without taking out a third mortgage.

I don't weld, so I've been looking at direct-fit cats. You'd think this would be a piece of cake, but there seems to be two kinds on the market for my van (06 Express 2500 base cargo 4.8L). One kind has the cat up near the exhaust manifold, and the other has the cat at the other end of the pipe, right near the muffler.

My van has the cat up near the front, as do the more expensive replacements (eg Walker). I can get a good deal on a Maremont 652638 -- which is supposedly the right part -- but it has the cat at far end of the pipe. The problem with that, although it looks like it will bolt up, is that the downstream O2 sensor wire is way too short.

To add further confusion, I look at the GM parts diagram for my van, and it has the cat near the muffler, but a much straighter pipe than the Maremont part.

Any idea what's going on? Should I just buy the (non-returnable) Maremont part and try to find a downstream O2 sensor with a longer wire?

Thanks,
Wes

StanVan

It seems to me that if the cat isn't in the same spot as what is there, it isn't the right part.

Twscarp

Any idea what's going on? Should I just buy the (non-returnable) Maremont part and try to find a downstream O2 sensor with a longer wire?

I don't know what side you need, but the Bosal brand looks like what you need from RockAuto: 2006 CHEVROLET EXPRESS 2500 4.8L V8 Catalytic Converter | RockAuto

canucklehead

any muffler shop should be able to weld on an aftermarket cat cheaper than buying a full section.

Wes Garland

Thanks, Guys --

I decided not to get the Maremont part ... not only is the cat shifted back on the pipe, it doesn't have a bung for a downstream O2 sensor, implying that it's fit to go into a different muffer, too!

I was getting ready to order a Magnaflow or Walker universal for a local shop to install (for some reason, they are convinced that universals are unreliable and want no part of the part-sourcing?!) ... when I clicked on the link above for RockAuto. Holy crap they are cheap. I'm going to have to figure out what that works out to "all in" when delivered to Canada.

That RockAuto page has the same confusion as this thread, though!! Look at the right-side parts for Bosal, Walker, and Davico. Davico sells one of each type! 59446 and 59369. What a puzzle!!

Twscarp

What I would do is jack the van up, take photos of the pipe, get a good idea what it looks like. Then go to the Bosal Catalog (Bosal Catalog), or Davico Catalog (http://davicomfg.com/catalogstate.aspx) see if you find the one you need, then order from RockAuto, worth a try.

canucklehead

I had mine done at carline with a walker cat parts and labour less than 300 bucks......

tech2

not a fan of the weld in cheap weld in cats...you get what you pay for....some can have low cerium content, the oxygen storing element in the cat....which results in a p0420 dtc setting after install.

oem parts are definitely insane...I prefer to buy a good direct fit complete y pipe and cat. If you must go weld in cat...get recommendations from people who have performed this repair and what brand they have used.

canucklehead

Walker is not a cheapie. They are oem replacement. Welding in a cat is way cheaper because you are not replacing 6 feet of custom bent pipe that is otherwise in decent shape.

tech2

cheaper only if you can weld it in yourself. the labour to cut out and weld in new cats offsets the y-pipe cost