Rocky Mountain Club B5

Discussion Forums => Maintenance => Topic started by: kt037 on July 08, 2004, 09:44:20 PM

Title: 1.8t downpipe/cat-converter install writeup
Post by: kt037 on July 08, 2004, 09:44:20 PM
about two-three weeks ago my Cat, broke off at the turbo flange. so i drove my car around (as little as possible) for about a week  with my 1.8t sounding like a peterbuilts jakebreak.... very annoying!

it took me a week of search but i finnally found a street-leagal cat, from, for 359.00.

 techtonics has a real nice hi-flow staneless steel unit but when i went to buy it, my CC didn't go thru (paycheck didn't post till next day), so i called back the next day they had raised the price from 415.00 to 475.00 (WTF?!?)

so i installed it the day before yesterday, and it was a pretty straight forward install, here is the very short writeup on a downpipe and/or cat replacement install, it takes about 1.5hrs

this is my first wrtiteup so bear with me... also i will be adding pics as soon as i get my camara back from my pops.
pb-blaster, breaker bar, 13- 17mm wrenches and sockets(normal/deep), big-ars flattip screwdriver, o2 sensor socket and beer.
possibly a sm propoane torch

 get cold beer and put car on ramps or stands.
1. make sure car is 100% cold.
2. remove the front o2 sensor with the socket
3. remove the 3: 17mm stop bolts connecting the cat/ko3 the bottom one is a PITA
4. from under the car remove the 2 clamps (14mm carrage bolts) from the connector section that connects the downpipe to the exhaust,
5. slide clamps and connector section back to rear of car. (use breakerbar/blaster)
6. remove the, springloaded downpipe hanger bolt (13mm)
7. (you'll need help with this part.) from  the engine compartment twist the cat 1/4-3/4turn counter-clockwise and pull forward, have your assistant help guide the downpipe up (the hanger is going to catch on the inner CV boot heat shield)
8. once you clear the bolt-posts on the ko3, rotate the cat clockwise 1/2-3/4 turn, so that the rear o2 sensor is facing downwards and hold in place.
 (this give you the most room to work)
9. from the bottom of the car , go in front of the axle with a swivel extention,  use o2 socket (or a >8'cresent wrench) to break the o2 sensor lose.
10. remove rear o2 sensor by hand, carefull not to twist the wires too much or they will snap (this takes finesse)
11. pull cat and downpipe out as one piece thru the engine compartment.
12. remove the 3:13mm bolts holdong the cat to the downpipe (they wil most likely snap and have to be replaced)

13.FOR hi flow downpipe (2.5-3") without cat, assemble both pieces, and install is reverse of removal.
13b. for cat replacement, install new cat to downpipe, and install is reverse of removal.

HINT: prior to reinstalling the o2 sensors twist the o2 sensor and twist the wires counterclockwise until tight, so that when you install them the wires will be straight when o2sensor is tightened in.
Title: 1.8t downpipe/cat-converter install writeup
Post by: ColoradoB5 on July 16, 2004, 01:10:48 PM
Mike good writeup!  I can't wait to see the pics.  How do you like it?

I can't figure out why I didn't see this before.

BTW, who makes that cat?
Title: 1.8t downpipe/cat-converter install writeup
Post by: kt037 on July 16, 2004, 05:15:39 PM
not sure the brand of the cat... it is the one from says that it is a OEM replacement, but it measures in at a 2.5"diam.and the OEM downpipe and exhaust measure at 2.25"

it folws well, better than the OEM unit i have a good solid pull thru 5900rpm...i am impressed with the part.