[XBMX]

I'm replacing my Magna Flow Cat Back due to a internal rattle. Called MF directly to ask about there High Flow cats/front pipes and was told by the fellow I spoke to that by using high flow fronts I would get check engine lights. They said to use the OEM type replacment. Any input appreciated.

 

[singlemalt]

More than likely. You'll need O2 simulators for the rear O2 sensors.

O2 SIMS

 

[SVTdriver]

I never had code issues running high flow cats

Thats the whole point, its enough to satisfy the o2 sensors and not throw a code but not restrictive like factory that has to meet much stricter standards


But if you dont have to pass a sniffer test for emissions just delete that crap and get the simulators mentioned above.....nothing is more high flow than catless

 

[SVT F-150]

Had a CEL with my Magnaflow hi-flows and these fixed it:

http://www.f150online.com/forums/exhaust-intake-systems/346911-gotts-o2-mod-pics.html

 

[jblot]

No check engine light here

 

[duncansvt]

high flow cats

I put a set of magnaflow high flow complete cat pipes on my 03 with no issues.i bought them from red lightning// but they are the dual cats that appear to be stock configuration at a glance .I even added bungs to the o2 sensor bungs to space them out of the direct exhaust path to promote better flow for which I received much dissent but still no check engine light.however I have not seen these four cat midpipes advertised or for sale anywhere as they might be discontinued.i agree with some of the other guys that you might need mil eliminators in line at the rear o2 circuits to keep that pesky ses lamp from illuminating..good luck

 

[hector svt 02]

Straight pipe ftw... lol

 

[svt-BansheeMan]

strait pipe for the rasp.

My truck never threw a code. It was tuned though.

 

[ZZZZAP]

I replaced the Random Technology cats that came with my Cannon exhaust with some universals from Pypes after they blew out with not even 1500 miles on the new engine. No problems at all with them.

 

[bet on black]

my magnaflows blew out after a while...but i had the rear 02s turned off in the tune anyways, so no issue, and would pass a visual inspection.

 

[ty.thompson1981]

Thunder bolt high flow cats and never had an issue due to the cats.

 

[WHIPPLE]

No issues with ARH high flows either.

 

[XBMX]

OEM system has four CATs and the high flows all have two. The tech guy at Magna Flow was cautioning me that the high flow systems tend to cause check engine lights. What am I going to gain with the HF system anyway???

 

[Jchetty]

In NJ, they are failing for visual no cats. If you fail, they tell you to sit in the back seat and they drive over a camera and show you where the cat should be.

So- just be careful if it is a driver. I know you are in NY, but just a matter of time.

I personally saw 2 ppl fail- 1 in Edison and 1 in Dayton.

They don't know the difference between pre, post, or welded shields. But they are looking- straight pipes won't cut it where I live.

 

[ty.thompson1981]

I don't think u will gain much going with hi flows. I didn't notice any power increase at all. The exhaust maybe a little louder that's it

 

[mdan575]

Pypes high flow cats here with no issues, I know when I sold my bassani high flows they were starting to come apart inside and they weren't that old.

 

[duncansvt]

high flow cats

after further comments thought I should add.it is highly unlikely that you will gain any performance at all unless you port and polish your stock exhaust manifolds.i did mine because I knew how bad they probably were.after pulling them upon inspection I confirmed they were ugly inside.i personally am not a fan of headers for a few reasons.first one is I live in California and we have to pass smog visual and otherwise.sure there are ways to get around it($).also header bolts coming loose ,rest of exhaust doesn't fit right etc..I did notice a performance/slight mpg gain with my magnaflow four cats because I spent 4 hours on each manifold making them look like art on the inside not including r and r and .to me it was worth my hands being numb for two days,every time I turn the key and drive.depends what you want.i use my truck for work so efficiency is my main goal,my 03 cobra drop top is for fun.good luck

 

[lockportdon]

Dynatech cats no issues

 

[SVTdriver]

I ran stock headers, bassani high flow mid pipes and bassani cat back when I was first getting started.
The truck had noticeably more mid range/top end power. It was "uncorked". Some off idle response may have suffered but it was not significant enough to matter.