Removing Catalytic Converter = Better Gas Mileage

Status
Not open for further replies.
OR you could just put some high-flow cats on, STILL be emissions legal, still get the power gain, and not have to worry about being a gross polluter?

My Town Car (89) had the stock 4-cat H-pipe. It barely passed E-test two years ago. The top cats started to come apart a few months later so they were temporarily replaced with some straight pipe.

So, this year, I replaced the straight pipe with TWO high-flow 3-way Magnaflow cats for an amazing total cost of about ~175.00.

Car blew ZEROES on CO, and WAY below the limits on everything else.

Back with my old Mustang, I ran it through the E-test (we have non visual in Ontario) with no cats. It passed. BARELY. So, cats are not a necessity to get through an E-test. Would I do it again? No. With the price of the Magnaflow ones, and the fact that there was no discernible difference in power output on the Town Car, it's just not worth it.

MANY Mustang dyno tests have shown that with a good set of HIGH FLOW cats, that the power difference between them and an offroad H-pipe is only 1 or 2HP. Obviously on the factory 4 and 6 cat systems, there is going to be a greater loss, but I think switching to a pair of high-flows and still being able to pass an E-test is a much more logical solution than simply slapping in a straight pipe and hoping you don't get nailed for not having them. I know, I got one last year, it was 380 dollars and the officer was being REALLY nice.
 
when i had my mustang, an offroad pipe was just as illegal as a pipe with high flow cats. only OEM cats were legal on my particular application. so if you're gonna get in trouble, at least make it worth it.
 
Originally Posted By: bdcardinal
when i had my mustang, an offroad pipe was just as illegal as a pipe with high flow cats. only OEM cats were legal on my particular application. so if you're gonna get in trouble, at least make it worth it.


I was pretty sure many of the companies making replacement H-pipes were "CA legal", could check BBK I guess to make sure.

It's legal to have two cats up here. The 2 3-way cats do the same job as the four original cats because the originals are not 3-way cats.
 
According to BBK, their high-flow catted H-pipe for your 98 is 50-state legal:

Quote:
All BBK 86-08 Mustang direct replacement X-pipes feature 2.5” diameter CNC mandrel bent aluminized tubing with two 50 state legal - high flow catalytic converters and BBK's unique die stamped performance Xtracter center X section to ensure maximum flow and horsepower.
 
There are cars like my GN which by design with it's single turbo and single cat, can't run a cat at the current hp levels. Originally I tried a Random Technologies high flow cat and the turbo wouldn't spool until second gear and I probably lost 150hp. There's no single cat that I'm aware of that would work with my car. And then there's the leaded gas issue lol.
 
Originally Posted By: OVERK1LL
According to BBK, their high-flow catted H-pipe for your 98 is 50-state legal:

Quote:
All BBK 86-08 Mustang direct replacement X-pipes feature 2.5” diameter CNC mandrel bent aluminized tubing with two 50 state legal - high flow catalytic converters and BBK's unique die stamped performance Xtracter center X section to ensure maximum flow and horsepower.


its not, they do not have a CARB EO number specific to 96-04. i worked as a student lane tech at a smog referee station. we failed more than a few cars with that exact setup. the only one thats legal is a weld in X that goes in behind all the OEM cats.
 
Last edited:
Status
Not open for further replies.
Back
Top