05 denali catalytic converter question

[BeaverGod]

need to replace at least one of my catalytic converters on my yukon denali (6.0).
a couple shops have quoted me prices to replace with one or both with an oem cat at $700 a piece with installation (not happening)
advance auto parts quotes about $275 for a replacement cat (not too bad assuming they actually get the right part)

i see magnaflows on ebay for $80....whats the catch here? does anybody have an experience with these, because ordering one or two of these is probably option number 1 on my list at this point.

also what diameter would the piping be on my yukon denali so that i can look around for generic replacements online?

thanks

 

[showtime1k]

no replys yet, yet im in the same position. deciding whether to order a universal or direct fit. can the direct fit be put on yourself? and do you have to change both cats if going with aftermarket

 

[BeaverGod]

no replys yet, yet im in the same position. deciding whether to order a universal or direct fit. can the direct fit be put on yourself? and do you have to change both cats if going with aftermarket

I'll be ordering replacement magnaflows from eBay around 280 each. They should be bolt on assuming you can get the old ones loose

 

[showtime1k]

ok, they got them on rockauto.com for 236 before coupon code, ill see if my bolts will loosen before i order, if not i think ill get the universal and get them put on if i got to pay someone to do it

 

[JennaBear]

I ran Magnaflows on my Tahoe, and have sold quite a few to customers (a couple on here). If you are interested in a quote, shoot me an email at [email protected].

Bottom line: $700 is WAY TOO MUCH for install, and $280 a piece is TOO MUCH for Magnaflows.

 

[ktmhans]

I just went threw all this. Far as i know and from what magnaflow has told me more then once. The 51019 is the only weld on cat that will meet the emissions for the truck. Most places are around$148 each. I finally decided to use the magnaflow y pipe with cats #93419. Not the oem one. The oem on has the 51019 cats on them. No one vould tell me what cats are on the 93419 set up but i was able to chat with some one that installed it and had no problems. The tubing looked awsome compaired to stock and i dont have to do any welding or cutting. Still a ss system. I was able to get it to my door for$352. I coudnt see not doing it. Sopposedly the oem y system $750 or so passes ca emissions.
Hope that helps, cant tell ya it worked yet cause its supposed to arrive on monday. I can tell ya how i made out

 

[showtime1k]

well just ordered a driver side magnaflow cat from rockauto, anyone have any problems with these, ive heard some people say they got a service engine light after install of a universal aftermarket and does it matter that one side is still oem?

---------- Post added at 02:44 PM ---------- Previous post was at 02:43 PM ----------

oh yeah, jennabear i emailed you but no reply

 

[ktmhans]

Ok just got it installed tonight. Freaking Sweat! Gotta pull the trans crosmember no way around it. But it fit perfect and the quality was top notch. SO much better then shock. i think it actually gave the truck a fair more amount of bottom end torque. Sond is alittle better as well. Have to nuts for the back to flange bolts. Mine broke right off.
I would highly recomend going this route, not sure if i said it before but it was magnaflow #93419 and i bought it from some thing like www.hotexaust.com. call them for a price dont just order it online.

 

[BeaverGod]

jennabear i just emailed you.

as for removing the transmisson cross member...what all does this involve and were you installing the direct fit bolt on magnaflow or a weld on unit?

thanks
BG

 

[JennaBear]

We didn't remove the cross member, just replaced the Y pipe and the cats.

 

[BeaverGod]

Ok just got it installed tonight. Freaking Sweat! Gotta pull the trans crosmember no way around it. But it fit perfect and the quality was top notch. SO much better then shock. i think it actually gave the truck a fair more amount of bottom end torque. Sond is alittle better as well. Have to nuts for the back to flange bolts. Mine broke right off.
I would highly recomend going this route, not sure if i said it before but it was magnaflow #93419 and i bought it from some thing like www.hotexaust.com. call them for a price dont just order it online.

what was involved in removing the trans cross member? also did you have a check engine light on? did this piece solve the problem?

thanks
BG

 

[ktmhans]

removing the cross member was easy 4 bolt and two on the tranny mount.I have the p 0420 code only .I cleared it 6 times.before i bought the cats. I couldn't get the back re y pipe out without removing itI haven't driven the truck enough to know it work for sure .
when you drop down the cross member have a floor jack under the transfer case .is the way better option I think thevn tryn to weld in your own cats

 

[BeaverGod]

well i just ordered two catalytic converters from a dealer on ebay. the 93419 part from magnaflow wont work for me apparently (having the 6.0) so i ordered the 93601 and 93602 parts from magnaflow that should be direct bolt on parts.

i will post pics of the pieces when they arrive hopefully before the end of the week and will take pictures of the install process.

i will also post any difference in mpg that these yield and will try to get a decent sound clip in the meantime to compare.

before i had issues with the cat i was getting 13.5-14 with city driving and 18.5-19 on the highway with cruise set at 70.

with a dysfuctional catalytic converter my mileage has dropped to 11.5-11.9 in the city and 16.0-16.5 on the highway with cruise set at 70.

all i hope to gain by getting these catalytic converters is atleast my old fuel mileage and for the check engine light to go away.

thanks for the suggestions from everyone who has contributed.

BG

 

[ktmhans]

So did you buy 2 cats or the y pipe aseembly? If you bought the y pipe i think youll.really like it. Mine couldnt have fit better. It came with all the gaskets. But no nuts. I would.rec going to the auto store and getting 8 new nuts. 6 for manifolds and 2 for the back tail pipe connection. My tail pipe bolts didnt even try to move, they just snapped right off.
Sweet on the 6.0. I can only hope i can get the milage u used to get. Ive never gotten over 14/17 but i cant say i use cruise at 70.
Time will.tell, try to hit everything with blaster for 2 days before. Especially the 2 nuts in the center of the tranny support that goes to the tranny mount.

 

[BeaverGod]

So did you buy 2 cats or the y pipe aseembly? If you bought the y pipe i think youll.really like it. Mine couldnt have fit better. It came with all the gaskets. But no nuts. I would.rec going to the auto store and getting 8 new nuts. 6 for manifolds and 2 for the back tail pipe connection. My tail pipe bolts didnt even try to move, they just snapped right off.
Sweet on the 6.0. I can only hope i can get the milage u used to get. Ive never gotten over 14/17 but i cant say i use cruise at 70.
Time will.tell, try to hit everything with blaster for 2 days before. Especially the 2 nuts in the center of the tranny support that goes to the tranny mount.

i bought two seperate cats. the y pipe assembly was not compatible with the 6.0 denali motor that i have according to the information i came across. the savings only being 50-60 dollars that i could find, i decided it wasnt worth the time and shipping cost if i got the part and it didnt work. the parts i ordered are listed above in my previous post. they are listed on magnaflows website as direct bolt on replacements that are 49 state compatible. they include some piping so welding should not be necessary.

 

[ktmhans]

that's basically a y pipe assembly ,should bolt on sweet

 

[BeaverGod]

Got the parts in today but it's 20 degrees here. Any reason why a shop would claim each side takes 2 hours to install? The best quote I've gotten is $350 to put these on

 

[ktmhans]

Got the parts in today but it's 20 degrees here. Any reason why a shop would claim each side takes 2 hours to install? The best quote I've gotten is $350 to put these on

I did mine in the driveway on my back at about 25 degrees, took me 3 hours, but i debated taking off that tranny support for hour and couldnt come up with another plan.

They have to make money

 

[BeaverGod]

its coming along...those bolts are absolutely BRUTAL to get loose. wish i wouldve gotten a cat back system because ive got to take the rear muffler assembly off anyway. all i care about at this point is that MF'ing check engine light staying off after i clear the code. also hoping to get a little sound out of these things but i can live with just the CEL. O2 sensors are in the most inconvenient locations on the cats as well...id hate to do this for a living.

update later.
BG

 

[BeaverGod]

both cats are now in place and bolted up. turns out i needed a new o2 sensor in the rear probably fouled by the bad cat. i will get a sound clip up later. as for my personal observations at this point....the cold start sounds way more aggressive. however driving the vehicle it almost sounds.....quieter under acceleration. there is a charge of sound right before each gear shift in the 2000-2500 rpm range but nothing outstanding. like i said the vehicle actually sounds quieter while accelerating. i have a CAI under the hood also. kind of kicking myself for not having a cat back lined up because i needed to drop the muffler assembly anyway.
compared to the fouled cat, the new system has improved throttle response and smootheness. havent driven enough to note a difference in MPG although my yukon seems to accelerate more effortlessly than before proabably again due to driving with a fouled system.

vid clip of the start coming soon.