cel came back on
 

i had a cel on my car for a while now. it was a p505 which is something to do with the idle control. i assume that it was a bad isc so i picked up a used one. i was told the used isc was still good. i put it on a few days ago and cleared the light. almost two days later it came back. i checked the code and its the same p505 code. is there something else that i should fix. the idle use to bounce around from 1k to 3k really fast and would die all the time. i havent had that problem since changing it but the light did come back.

p505? Are you sure it wasn't a p0505 or a p1505? OBDII format should be 5 digits total, one letter and four numbers and the first number can only be a "0" or a "1"(or "2" or "3" but not on a pre-2002 vehicle)

i used the scaner at checker and it came up as p505, it may have just dropped the 0 form the beginning. thats what i thought or i could have read it wrong. i would check again but i cleared it so it might be a few days untill it comes back.

What year car is this?

its a 96 tsi awd

alright its back. it is a p0505. so where should i go from here?

just block off all that shit. Maybe im thinking that will cure the problem, however i could be wrong. Ask some of these more experienced guys and if they say the same, hit up QPR.. they have plates for this.

You could block off the faiv and the isc but it would idle like $hit if at all...

I would ohm the isc and see what it reads, I am not an expert on 2g's and my dsm cd manual up and walked off so I cant offer much other help, sorry.

Remove the light from the cluster.

[QUOTE=Sean485]You could block off the faiv and the isc but it would idle like $hit if at all...

Actually it will idle just fine. Startup wont run "fast idle" though becuase there is nothing to speed the idle up until its warm. But if those sensors are missing I think it will pop a cel anyway on a 2G.

Eh, you might be able to get it to idle right when the engine is cold or when its warm by playing with the biss but I think you would have alot of problems getting it to idle right for both because of the ecu dumping in extra fuel for the extra air it "assumes" is going to be getting past the tb plate when its idling cold. I have no experence with it personally but before dsmtalk went down I knew of several people who built an entire blockoff plate for the isc/faiv portion of the tb and they said it ran good when it was warm with a solid idle but when it was cold they had to keep thier foot on the throttle or it would stall.

IMO it would be better to "fix" the problem rather than just removing the entire system or just removing the cel bulb because that light could tell you if something more serious is possibly going out but its not my car ;)

My $.02

the light is on but its not doing the idle surge thing so im just going to leave it alone for now. i have to do a timing belt next month so ill take the isc off then and check to see if its good. and i dont want to remove anything id rather just fix it the right way.

Way to not think like a DSMer ;)