Contour Enthusiasts Group Archives Forums Branches Western Canada Your opinion on this....

Alrighty.. heres the skinny.

Gonna do the mil's later this month, have already ditched the middle cat. Therefore I will not have any. A certain person has said if I were to add a "high flow" cat back into the system (middle one) I would not loose any performance gains by adding a chip.

Now this is what I am trying to understand. High flow cat is just this, straight through. Does not increase back pressure significatly at all. So my question is this, has anyone added a chip, kept there mid cat and have a dyno run, and or has a chip with no cats and felt a loss? If this is the case I will simply remove the factory one from the headers and use that as a mid cat to increase backpressure.

Any thoughts?

I would just go completely catless. I did on my 'tique, I used a superchip, and a set of MIL's from Dallas Mustang. No problems whatsoever. I had a true dual setup too though...

I would not want to add just one main cat... Cats are most efficient when closer to the engine (heat), put it too far away and it will be just added weight and a sound limiter. I would rather have a very large resonator in its place. Plus we don't have any really strictly enforced pollution laws... so why have them on the car?

If you can tune it without the cats (least backpressure) you should make some decent power. Tuning is the key though. I was losing power (but dyno) with my chip in and this setup then I was with the chip out.

I didnt feel any power loss. though my butt isnt the most accurate way of measuring power.

The car was very peppy with no cats and a true dula 2" system consisting of 2 resonators per side. Up top (where the duratec lives) was great for power, it flowed awesome. Yet down low for cruising around the car seemed easier to accelerate and did not require to downshift much at all at lower rpm's. though maybe my tranny mods had to do with that...

Of course your mileage may vary

with the chip my car ran the exact same times as it did without it. with the power it lost it made up with a higher shift point and the work it did with the tranny.

the car felt better without it with the exception of shifting, it just seemed to have more power especially down low. and if you shift manually you can get the higher shift point anyways.

I'm currently catless, but due to Ontario emissions I gotta put a main one on.


Ask just about any coffee truck driver, they'll know where you can get a hot smog (about$150)

Your 'middle' cat isn't its a resonator. The zetec cat is bolted to the exhaust manifold , between the rad and block. Removing it will not affect smog but will affect sound.
Cat - resonator - muffler