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Cat delete pipe for 2002 ford focus

17K views 33 replies 12 participants last post by  whynotthinkwhynot 
#1 ·
Hi all,
I'm looking for a cat delete pipe for a 2002 ford focus zx3. I've been looking online and haven't found anything. I know there has to be a company out there that makes these. Can none point me in the right direction?
 
#5 ·
Those "shorty" headers have been found to do very little in any gains. Be prepared for a very loud exhaust if you are running with very little back pressure / muffler in the rest of the exhaust. Why are/do you want to pull the CAT?

The companies that do make an off road pipe usually expect a full length header. Pulling the CAT alone will not make nearly as much performance as pairing the off road pipe with a good header
 
#7 ·
I bought the OBX setup from a local seller. It didn't make mine much louder. But, I already had my Bosal catback installed. So it was louder than stock anyway. I only purchased it for the downpipe because I couldn't find one separately. I did attempt to install the shorty since I had it anyway. I have quite an assortment of tools between my son and I. But for the life of me, I couldn't get all the header bolts installed after trying for hours. I even had some ARP bolts so I wouldn't have to mess with the crappy studs. If I had the money, I would have done it the right way ( SVT ). There are inexpensive aftermarket converters around if you can't afford the full swap. Plus, I think the downpipe may be clogged or something. I've got a constant vibration lately and the exhaust has definately changed tone in the last few months. The weather has been absolutely crappy for weeks now and I don't have a garage. I will take it apart some time and see what's going on.
 
#8 ·
I also just really need the down pipe. I could care less for the header. Most of the ones I've seen look cheap and of low quality.

I would've never believed someone doesn't make a cat delete pipe for these cars but it looks like that is the case.
 
#9 ·
I am not sure, but I don't think that down pipe from the OBX will fit directly onto the stock manifold. And as far as my knowledge is, they never made a cat delete pipe for the regular Zetec. The SVT gets the off road pipe because it has it's catalytic converter underneath the motor instead of in front of it. You could always have an exhaust shop custom weld one for you but that might prove to be a bit costly.
 
#10 ·
deleting the cat by using the time honored method of taking the cat off and punching out the honeycomb with a long rod, will get you a constant Check Engine light, make the car sound worse than before, and brand you as a stupid ******* by anyone who knows anything about cars.

Cats last practically forever unless something has gone wrong with the engine. But if the engine has a problem they will plug up eventually.
 
#16 ·
"...Removing the cat doesn't make you loose power..."

Yes, it does - but to be explicit, it does for 99% of your driving. When you remove the cat the computer goes into open loop all the time, and uses a suboptimal preprogrammed fuel curve - that curve does not matter at WOT of course. Also the loss of backpressure from the CAT reduces low end torque. Granted - you see a gain of high end HP at high RPM because of the lower back pressure and because at WOT the computer is basically dumping fuel in as fast as the engine can take it but the tradeoff is less low end torque.

Basically the only way it helps give you any HP at all by punching out the cat is if you drive around above 4-5K RPM at WOT all day long. Great if your drag racing - pretty terrible for most regular driving.

If you want to do it right, you delete the cat with a custom-welded exhaust, and replace the engine computer with a different one programmed for no cat. THAT is the only way a typical driver will see a HP increase by removing the cat. Incidentally, a cat with an intact honecomb fetches a hundred bucks from a platinum salvager so you definitely want to do it properly.

But, it won't gain you much HP. The exhaust system in the Focus is pretty damn good for a stock car.

Most people I know that do the punch-out on the cat are buffoons who already have something wrong with the car - their CEL is already on - and they go to Autozone and get the free OBD test, which tells them the cat is bad - and since they don't have the $200 for a new cat, nor the education to realize the problem isn't actually the cat it's something else, or tools to actually troubleshoot the car properly - they punch out a perfectly functioning cat then spend the next year trying to convince themselves that they "increased performance"
 
#20 ·
There have been proven gains on the focus to show that it does gain power albeit small if still using a shorty header but bigger ones mainly due to the whole manifold being replaced by a long tube header, on the SVT removing the stock cat will not gain hp but you will gain tq has that motor is already pretty much maxed out from the factory. Just like the myth that a bigger exhaust will make you loose power as well is also false (for our cars at least) 3" exhaust has been shown to be the best, that's why we recommend 2.5" or bigger. Loosing power due to the O2's not being able to meter right is just boloney. Please read through our performance sticky threads before posting any other false information. Not every car is the same so don't assume that what goes for one car works on ours. Also when removing the cat it is a must to get a tune to correct any problems that may arise from the deleting it (like the CEL) plus it optimizes any other mods done to the car so you get the maximum benefit from them.

Performance sticky threads HERE
 
#25 ·
It does cause any car running OBDII to have trim issues and fuel metering issues I don't want to argue. However dynos, dealerships and tuning techs and performance shops dont all lie, the o2 sensors arent there for performance but there failure or lack of proper function will cause performace issues.
 
#21 ·
For those stating that by removing the cat you will loose power, you are clueless. You gain power by removing restriction. Either get a tune that turns off the rear o2 sensor or install an o2 cheater to trick the ECU.

Please do some research before giving others advice.

Catalytic converters need to reach and maintain a certain temp to work. That is why they are positioned close to the engine. Moving them further from the engine renders them useless.
 
#22 ·
For those stating that by removing the cat you will loose power are clueless. You gain power by removing restriction. Either get a tune that turns off the rear o2 sensor or install an o2 cheater to trick the ECU.

Please do some research before giving others advice.

Catalytic converters need to reach and maintain a certain temp to work. That is why they are positioned close to the engine. Moving them further from the engine renders them useless.
X2 on this. there may be a reason that the zetec and svt focus both regularly perform BEST in open header configuration on the dyno and at the track. the less restrictive you can make the exhaust the more power you will make.
 
#23 ·
"...For those stating that by removing the cat you will loose power, you are clueless. You gain power by removing restriction. Either get a tune that turns off the rear o2 sensor or install an o2 cheater to trick the ECU..."

Apparently reading comprehension is not in your abilities as I stated pretty clearly:

"...If you want to do it right, you delete the cat with a custom-welded exhaust, and replace the engine computer with a different one programmed for no cat..."

For the OP asking for a cheater pipe - because he's too cheap to walk into an exhaust shop and have a pipe bent with some flanges welded onto it - do you honestly think he's going to spend the money on a "tune" or o2 cheater? Really?

For most people out there looking to delete the cat, all they want to do is punch the cat out and tell themselves they are increasing HP. They are not interested in actually removing the cat properly, and reprogramming the ECU. And if you think their car has ever been on a dyno I have some beachfront property for sale in Florida cheap.

Please don't encourage the wannabes in the performance forums. We have way too many kids driving around with chrome exhaust tips, fart cans, and punched out cats who think their Focus has an extra 100hp.
 
#27 ·
You are 100% right except you left out that when the and down stream o2 sensor detects high emissions it leans out the fuel trim which will cause poor performance. Also whn the enginelight comes on due to o2 issues the computer turns to a preset loop.
 
#32 ·
My point was that you have to look at cost/benefit when making performance mods. I have to believe the other posters saying to leave the cat alone understand the same thing.

If you ask people "is it better to mod a 1.8L or replace it with a 2.0L and mod that" quite a lot will say to start with the 2.0 - they say this because they understand that you can spend thousands on a 1.8L increasing HP and far less just swapping it out for a larger displacement engine that has the same amount of power as the modded 1.8L.

In other words people have no problem understanding cost/benefit calculations when it comes to getting more HP with increasing displacement.

But, for some reason when it comes to what I call "barnyard performance mods", a lot of people's logic and understanding of cost/benefit goes right out the window.

They myth that 20-30hp is just available for 3 hours Saturday morning's work with about 25 bucks worth of tools and $100 worth of parts just doesen't seem to want to die.

From the looks of it the OP left this thread a long time ago, so we are just arguing for the fun of it, now...
 
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