so, i just remembered, i wanted to ask you guys about my friend's 08 rabbit. he put a exhaust and a SRI on it, and the car is throwing codes as running lean. but he's brought it to the local speed shop, and there's no tune for the car yet. also, the SES light is on and off, and to me, it seems like when it's real cold out, it comes on, and when it's mediocre or warm out, it stays off.

so, basically my question(s) is/are... can a simple SRI and exhaust make car run lean enough to damage it? what can he do to fix if untunable? and would the fact that it's so cold out along with the filter being a high flow filter(more air, and more dense air = alot more air for engine) be making it run lean? if so, he wants to keep it on, cuz, in summer, it wont throw code.

sorry, i didnt know where else to post this thread, no "other cars" section here

 

Sounds like it could be pre-cat O2 sensor issue. O2 sensors need heat to work properly so they have a heater installed to get them up to operating temps quick, if the heater is malfunctioning or not working the O2 sensor won't be able to give proper data when it's cold and they have a lot to do with how the car determines mixture. The car should be OBDII which means it should have a standardized diagnostic port as well as standardized codes, you should be able to grab those from the free Auto Zone scan and look them up.

 

yea. we did get codes, didnt get the exact code, but it said intermidiate(sp?) signal : lean mixture. and he put the stock intake back on for about a week now, and it hasnt come back on at all, but he put it back on again yesterday(didnt come on yesterday) and came on today while it's ~20 outside. (he kept exhaust on though, so i think we can exclude that)

the guy told us there might be a hole in the SRI somewhere, causing it to be a bad signal? but problem with that theory is, he's tried 2 of them now, doing same thing, unless it's a coincidence 2 have a hole or bad SRI design.

the things confusing me. lol. friggan high tech euro cars.[:@]

 

you put the stock back on and its fine now?

Seems like a common problem when you put a SRI or CAI. Right off the back I knew this question had to do somethign wit CEL coming on. One of the problems could be is 02 sensor or the MAF sensor. The Engine will throw a CEL light if the proper adjustment has not made.

btw when you installed the intake did you disconncet the negative battery terminal? If not, you should go do that right now and leave it unhooked for like 5 minutes, then hook it back up. It resets the ECU and lets it recognize the new intake.

 

yea, we did all that to install it. and i have a feeling it's just cuz it's a damn VW.. he's looking to get rid of the car already, only has like 12xx miles on it