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Discussion Starter · #1 ·
Well someone said to clear my CEL (which was caused by my CAT-delete pipe) all I had to do is unhook my battery for a while & when I hooked it back up the CEL would be gone. Well the CEL did not go away & now when I start my car it revs up & down about three times then levels out. When ever I release the gas like when I come to a stop sign or light it revs again & then evens out. Does anybody know why it would do this just because I unhooked the battery for a while?

Thanks,

-Paul

BTW - '99 B5 1.8T AEB n-DBW with Tiptronic
 

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Put the catcon back in. You don't give up enough horsepower to justify giving the finger to all the people who would like to have clean air to breathe.

Your engine is surging at idle because your throttle body is dirty and the engine can't get enough air when your foot is off the gas, so it has to open the throttle by itself -- and the AEB's throttle kinda sucks at the whole "finesse" thing.
 

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Discussion Starter · #3 ·
Your engine is surging at idle because your throttle body is dirty and the engine can't get enough air when your foot is off the gas, so it has to open the throttle by itself -- and the AEB's throttle kinda sucks at the whole "finesse" thing.
Thanks for the fast response, I will try that when I get home:thumbup:


One of the reasons I put the race pipe on is because the stock CAT broke at the flange that connects to the turbo which VW would have replaced since it's covered by law for 7 years, but they are saying because of my mods the motor was putting too much horsepower for it to handle so it broke :rolleye: and I didn't have $450 + install for a new one so I went with the race pipe which was only $150 + install to free up a few more ponies, but when I get some more cash I am going to put a CAT back on.
 

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Thanks for the fast response, I will try that when I get home:thumbup:


One of the reasons I put the race pipe on is because the stock CAT broke at the flange that connects to the turbo which VW would have replaced since it's covered by law for 7 years, but they are saying because of my mods the motor was putting too much horsepower for it to handle so it broke :rolleye: and I didn't have $450 + install for a new one so I went with the race pipe which was only $150 + install to free up a few more ponies, but when I get some more cash I am going to put a CAT back on.
Good boy.

Anyway, even after cleaning the throttle body (use aerosol throttle body cleaner from the auto parts store, DO NOT USE OTHER CLEANERS), you'll still have some surging for a couple of days unless you have a VAG-COM cable that you can use to tweak your throttle's idle position without having to wait for the engine computer to figure it out for itself. However, the surging will be much less, and the jerk that happens when you let off the gas (which you must have, because everybody with an AEB has it or had it) will go away.
 

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I assume you mean irratic idle. Most Passats should do this. All mine did. It goes away after you drive it for awhile. I dont remember exactly but it took me about 10 starts or so and then it goes back to normal. Correct me if Im wrong but thats what mine has been doing everytime I unhook the battery for new mods or stereo installs/changes.
 

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throttle body adaptation probably needs to be done. VAG-COM can do it or you can try:
open the hood, open the door, key in ignition to on (do not start) and wait two minutes - you should hear it clicking.
 

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Your stock cat could have been welded for about $20. You might want to check your motor and snub mounts as they usually lead to cat flange separation.
 
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