hey man. i read your post about your exhaust system. how much did that run you after all was said and done. you did (2) high flow cats, an x-pipe, and then two mufflers and out the back with duals, right? thanks man.

 

I was into it for just over $700 including the high-flow cats and the labor to gut my pre-cats. True-duals all the way back with an x-pipe.

Sounds great, I couldn't be happier!

People in the back seat get some drone on the highway at certain speeds, but that's their problem!

 

did you notice any loss of low end torque. every one says when go to high flow cats that you lose low end torque. is that true?

 

Didn't notice any loss, but I had some exhaust problems (clogged cats) so it's hard to say because it just pulls harder all over now that the restriction is gone.

I also have an ATI supercharger, so I can't really say how it affects a non-blown truck.

But before the blower, I ran a single Magnflow exhaust becuase I didn't want to lose low-end, as I read the same info about losing low-end torwue.

 

how much do you think it costs to have high flow cats put in ordering them from an exhaust place? I already have a flowmaster force II cat back exhaust, but wanna get some high flows. I went to some performance place today and they waid it was gonna be expensive, the guy didnt give me a price though. Why would it cost so much to replace the old cats with high flow ones?

 

Profit margin.

Buy them on E-bay ans save yourself a bundle.

One place I called wanted like $300 each, when they are all over E-bay for like $60.

 

ok cool. I always see them on eBay and they are so cheap compared to what the performance shop is saying.

I want to get some magnaflow high flow's but i dont know if i need one, or two? (I'm pretty sure 2, i just wanan double check with somebody who knows what their talkin about) Also, having the flowmaster catback exhaust, what size tubing should i buy for the converters? My original thought was 2.25 inches, but i think the flowmaster piping is 3 inches.

Thanks for your help so far Jordannotmike - i'll defintely order these things off ebay at the best available price. What ones would you recommend off ebay - they all look the same, or even generic looking?

John

 

if its a stock 4.6 or 5.4, youll need 2.5" cat. converts. Ive heard that 2.25" pipe protects the loss of low end torque, especially on true duals.

 

i went with 2.25" true duals w/x-pipe and that really woke up my bottom end.

 

so i can get 2.25's and have them put on without worrying about the size of the rest of my pipes?
And i need two of them?
I went on to ebay today and found a whole bunch but then they say OBII, or ODBII, something like that, and talk about O2 nuts i think - does this apply to specific models/years of truck, or can i order any magnaflow high flow cat on the page?
THanks!!!

 

I thought I knew what the part number was. I bought my cats, but my installer said htey were incorrect.

He gave me credit for my incorrect Magnaflow (non-OBDII) cats, and gave me OBDII Magnalfow cats instead. I didn't get the part number of the new cats.

 

OK OK. Let me start a long drawn out post and see if I can keep anyone with me by the end. Here it goes.... I know there is 4 cats on a truck, is it worth it two replace two of them with high flow cats, then an x-pipe and then glass packs and then out the back or is that pointless. I am looking for some deep rumble. Any suggestions would be helpful. I don't want to sink a wholw of money into it, in the ball park of $400 or so. I do not want to have to worry about O2 sensors and bungs and having lights on my dash come on. thanks.

also if I go to a 2.25" pipe (1. is that possible - 2. would I do that after the cats, x-pipe, or when) would that give back the back pressure that I had lost.

 

That's what I did. Left some of the factory pipes (like where the sensors are) intact, so the sensors are in the same place they were. I also just gutted the pre-cats, so it looks like they are still there.