im wantin to put a CAI and high flow catalytic converter on my Blazer LS, 4x4, 4.3L. i know where to get the intake, but where should i look for a good high flow? ive never thought of the high flow much, but i wanna try it. also, what kinda "symptoms" will the Blazer have with the high flow cat? (i.e. power increase, sound, low/top end?)

thanks!!

 

not much of a difference with a high flow cat.. I dont have a cat on my jimmy, and I dont notice a difference, it grumbles a bit more, and the exhaust smells more, that is about it LOL

 

I agree not much change Maybe a slight more noise but with a CAI you won't be able to tell because the noise from the CAI will drown it out. CAI will sound like you have more power but it won't. Most stock factory air intakes allow more air than a stock engine can use. Without a supercharger to force more air in your wasting money for looks & thinking your gaining. I spent my days around flow bench testers & race tuners.

 

You may get a CEL for the downstream o2 sensor because of the high flow cat, if you do just get some spark plug non foulers and raise the sensor out of the stream. The CAI is mostly for an increase in noise, but its a nice tone lol.

 

50lbcat, I think you are referring to something I was wondering about. My '98 ZR2 V6 4X4 has no guts in the cat at all. So I was going to replace it with a high flow cat (Magnaflow...price is my reason $90.00 -vs- $280.00). I'm not sure what you mean by CEL, but would that also mean the downstream sensor would throw a DTC with a high flow cat? I have my engine out right now, but it did have o2 sensor DTC's...would the cat having no guts been one of the reasons for a trouble code? This is a question I was going to search/post on this forum anyway down the line. But this thread seems very relevant.

 

By CEL I ment check engine light, a DTC. Some high flow cats will throw the trouble code, some dont. If your cat had no guts and the code was for the downstream sensor then thats why. The downstream only monitors if the cat is working and with no guts it wouldnt be working lol. You can get rid of the code by installing the spark plug non foulers. Its very easy, just remove the sensor and put the non fouler on and re install. All it does is raise the sensor out of the flow so it reads cleaner air, fooling the computer into thinking the cat is doing its job. There are more specific how to's out there and I dont remember the exact part number for the non foulers but they are made by Dorman.

 

hmmm. must be different on these. i had a buddy back home put a Flowmaster and High Flow on his Dodge pickup (360ci) and he said he noticed quite a bit in power increase. he did this exhaust mod after a chip and CAI, so maybe the exhaust just helped with the electronic stuff (?)

im not sure about performance on gasoline engines, im a diesel guy. but due to the lack of money, im "stuck" with a Blazer haha! i do love it, but want somethin bigger. this will soon be my little toy

 

CAI is a great idea, for the manufacturer, and a total waste of money for the buyer. The main reason is that the air must be warmed, making it less dense so the fuel mixes with it more completely. This happens right under the throttle plate, in the plenum. Why bother installing a CAI if the air has to be warmed up? Save your money. The factory air inlet system is capable of flowing more air than this engine could ever use.

 

if he noticed a HP gain from adding a high flow cat, he was imagining things, because it really does nothing, and what it does, you could not notice because the numbers would be so low

 

I saw flow charts on different engines when a friend of mine owned a tune shop & did a bunch of flow testing & work, & your 100% correct Capt. Guys that buy CAI just don't know or care. It is Kool looking & sound good hearing your engine sucking air so they must work, & they cost a bunch of money.
I ran a high flow cat on my 97 Blazer 4x4 & never had an issue with my CEL.But with a High Flow Cat & a Pro Flow turbo muffler I gained nothing, except a nice exhaust sound, & lost a little low end torque. The Cat was installed to replace a melted one, the muffler was a choice of mine just for the nice tone it made.