I never thought of heat-shielding. Good call.

As a side note Mario....you REALLY should get that pre-cat off the car ASAP.

 

I would but my mechanic insists that I would pop my engine in not time flat if I did. That pre-cat is 14 years old (as is every other part on the car) and the car is still running well (approx 87K miles). As soon as the motor gives up the ghost, I will consider doing the dp + new cat + exhaust. Trouble is, this car will not die! Living up in the Pacific NorthWest, this car does not run in a hot summer climate; that and timely servicing has made me pretty fortunate in terms of having a reliable FD.



If you have another angle that I could use to convince my mechanic about putting on a dp, I am all ears!

 

First, the pre-cats had a habit of failing/collapsing at much lower mileage than yours. When they do, they damage the engine from heat and back-pressure. Secondly, the pre-cat is only there a a concession for emissions DURING WARM-UP. After the engine nears operating temp, your main cat handles everything, so the pre-cat is redundant. Removing it will not jeporadize emissions if your state has them. Third, it creates tremendous under-hood heat. I'm sure you've opened your hood after running the car and noticed it. That heat bakes EVERYTHING under there, especially all the vacuum lines, solenoids, check-valves and plastics associated with your sequential system. It's unnecessarily hard on those and reduces their life. They get brittle, crack, leak and you have alot of trouble that can be difficult to diagnose. Fourth, installing a good quality downpipe, preferably in stainless will reduce back-pressure, which allows your turbos to spool easier which extends their life. And since it's also gives your car a significant increase in performance (I'ver heard up to 20 hp on a chassis dyno...10-15 is probably closer), it's one of the few reliablity AND performance mods you can do.

Your stock main cat and cat-back will provide more than enough back-pressure that boost creep will not be a problem, so I have no idea why your mechanic thinks you would "pop" your engine. But he sounds conservative. That's good. So am I and my car is still mostly stock with 86k. I tend to choose mods very carefully and usually for reliablity. But if I bought your car tomorrow, this is the first one I would do. If you have the money, I would get a quality STAINLESS downpipe (Bonez, Pettit, HKS) and have it heat-coated or simply wrap it with some header wrap. This reduces radiant heat under your hood even more and will quiet it a bit....maybe even more than your current pre-cat. The DP with header-wrap will run you maybe $250-$300 (it's been along time since I looked at prices). I do my own work, but if you have your mechanic install it, double that for installation.

 

Thanks for all the help guys I will check that out. (the heat shield and the down pipe)



My bushings are going to get done soon so while thats going on I should do the pre cat.



My car is BONE STOCK with 83,000 miles It is my daily driver. Anything to help it out would be great. Thanks for the advice.



Stupid question I know but how do I get rid of the pre cat?

 

The pre-cat is essentially a stock downpipe with a small catalytic converter (the "pre-cat"). Remove it, and reinstall a true downpipe.

 

any brand name recommendations?