High flow cats?

[jabartram]

I called random technology today about a bolt in high flow cat for the Alero, I was told that they discontinued them, they were aparently having alot of trouble with them, Has anybody had any problems with other highflow cats, does anybody else make bolt ins for the Alero, or do I need to go with a universal high flow cat?

[Fast Eddie]

I got a univeral High flo Catco one, cheaper and just as good as the random one.

[Redog]

I have the random. I've never had a problem, but I don't have the one for the Alero. I think mine is for a Mustang or another larger V-6 / smaller V-8.

I did have to buy a O2 sim. on PFYC

[ShortysTRM]

Have you ever had trouble with your O2 simulator? I don't see how it could keep the engine running correctly without running lean or rich...

[Alerosince99]

i have a carsound or magnaflow with 2.5 in and out. No problems and dont throw any codes.

[loudalero]

ok I have a dynomax 4" bullet muffler in place of the cat and a o2 sim and have had these on my car for a couple of months with no problem but I have not gotten to drive it to much either, its been in the bodyshop but its worked so far.

[Fast Eddie]

Originally posted by ShortysTRM@Jan 21 2004, 12:06 PM
Have you ever had trouble with your O2 simulator? I don't see how it could keep the engine running correctly without running lean or rich...
I don't have a sim (and you shouldn't need one w/o heavy mods) but I have had no problems with my HF cat; stock sensor woks fine. I'm getting to get a W/B sensor at some point but not soon.

[jabartram]

We run a single o2 sensor? and what is a W/B sensor?

[jabartram]

I'm looking into a full custom magna flow exhaust, or flowmaster, instead of the slp? alot depends on the price!

[dopey]

u wont notice any difference or get any real gains with a highflow cat unless u have alot of motor work done.

in my opinion ur money could be better spent else where.

[3.4Alero]

Some people w/o lots of other motor mods have actually seen a decrease in performance with the high flow cat.

And yes, we run 2 O2 sensors.

[Final-Reality]

W/B means wideband, it can give you on-the-fly feedback and is used for engine tuning

[loudalero]

About how much do the wideband o2 sensors run because they are alot more accurate for gauges also but if you know how much and were I could pick one of these up that would be great.

[Redog]

I never had a problem with the O2 sim. in my car. Been in since July. If you have your O2 sensor relocated to in front of the cat, it won't turn on your SES light

[Redog]

As for a decrese in preformance it depends on how big of an opening you get on the cat. My Random Tech is for a big v6 or small v8 but the inlet/outlet is only 2.5". My entire exhaust is custom but still only 2.5"

Going too big like 4 or 5 inchs WILL slow you down. You need some back pressure to keep your car going. No back pressure, you go slower

[Final-Reality]

wideband O2 sensors are useless without the proper equipment to read them, which is why the're generally only sold with kits, like a TEC3 unit...

[Fast Eddie]

or a guage??!!

The real problem is tuning. VERY simple tuning can be done via a AFPR. Of course tuning for the whole fuel curve does require more complex means (IE new FMU/ECU)

An AEM UEGO setup can be had for less than 5 bills and close to three if all you need is the sensor and harness.

[geedog66]

i just finshed my full 2.5" full exhuast on my 2.2 ecotec no codes were put out so far im still running both o2 sensors still

[AleroSS]

Im confused here, for people saying they ran 2.5 setups, yet still had both O2 sensors, does that mean they left the stock cat in (cuz then it wouldnt really be a 2.5" system) and if not, where is the o2, and where does it have to be placed in aftermarket/custom setups (pics would be VERY appreciated)

[bdyman]

here is my opinion on high flow cats.....THEY SUCK!!!! no need for one the gm cat`s flow just fine and if you do have one the pcm would need to be reprogramed for the high flow to get the proper effinceny out of it
i had a high flow cat on my car and all it did was rob power i felt no difference with it on and all it did was make gas milage poopty i went through 2 rear 02 sensors and a servie engine soon light on all the time and no company makes a 02 sim for the ecotec`s
so now i have a catco oem cat 2 1/2 in 2 1/2 out a new rear 02 sensor and as soon as i had it installed a felt a huge difference and gas milage went up right away i cleared the code and my car runs great
in my opinion don`t waste your money on something like a high flow cat