Hey all first post here on this board and its a bit of a long one. So here's the story I went and got this 99 a4 t/a from a stealership (cue villainous theme). On the test drive i went down the road where I couldn't be heard behind the Fred Meyers on Sprague and proceeded to unleash a monstrous 1 minute long power brake burnout to see how she ran and if the drive train felt tight. Results were the tires roasted effortlessly and the exhaust note was enjoyable. Long story short I went back and bought it after a couple spirited pulls. No check engine lights no obvious issues until the next day. It triggered a couple 02 codes and consulting google I swapped out to Bosch rear vette sensors ( my front sensors were tripping the code) to compensate length for the hedman lt's that are in there. The car still triggers o2 codes but not as frequently and so far only for a catalyst inefficiency on bank 2. It also backfires on take off and acceleration not every time but way too much for me. My mods are 3 inch exhaust with an ory pipe running no mufflers and the German long tube headers. I believe it may have a cam as well due to the idle surge at stoplights and the tremendous mid/top end hit it delivers. I am thinking this car is unturned but not sure because I got it from the stealership... sorry for the long post but this is bugging me because the car is very powerful when the foot goes down. I have RAN away from a 6 SPD bmw m5 from a dig up to 120mph twice and also walked a TT Awd 3000gt from a roll 3 pulls consecutive with exact results so it definitely runs strong. Opinions will be GREATLY appreciated as I am very tired of solo pondering these issues.

 

Ponder being an idiot w/ that "1 minute" burnout..
Try the correct forum. Tune/diagnostics.
Be sure to bring some sound data,[data logs, tune file, etc], other than bs about "walking" a M5, etc.

 

What ya gonna do, what ya gonna do when they come for you....lol

As far as the post, I would just get the rear o2s tuned out if they aren't already c they aren't going away computer wise on their own....if the front o2 sensors are acting up then have someone with a snap on scan tool or equivalent scan the car and make sure they are opening properly...

 

Wow what a great help you are! NOT. Responses such as yours are worthless and have no place in the forum. Go the read guidelines again. If you can't be helpful keep your rude responses to yourself. I'm only looking for basic second opinions other than go to a tuner or similar.

 

Well I replaced the front o2s with the vette rears and it did help with the codes but my main concern is the backfiring and idle surge at stop lights... every time it tripped front codes it was for the heater circuit in the o2 that code no longer trips since I installed the vette sensors I now only occasionally get the inefficient bank 2 but the weird part is the ses light comes and goes without being cleared. I'm hoping a tune will clear it all up because the backfires can be embarrassing.

 

Vacuum leak

 

Could be... if I have the time this weekend I'll do the leak test to it. I have been driving my gmt800 instead of the t/a just in case.

 

Go to a tuner or similar.

 

Hey great another uninformative reply that is totally useless and in no way actually pertains to the questions asked. Is this forum for helping people or acting like an *******? All I was asking for was a second opinion or just a quick educated guess not to be treated like some punk kid who wants to hear his blow off valve louder. I'd really appreciate the help because the transmission in my truck **** the bed yesterday... But Thanks anyways guys...

 

The best answer was the second post given. You need to take the car and make sure its been tuned. You dont have cats and you are getting o2 codes. Thats pretty standard. You could even get other false codes if its cammed etc. There isnt a miracle answer that is going to just fix your issues. Your best place to start is going to be to make sure its been tuned and check the front o2's with a scanner

 

Thank you. Going to a tuning shop is what I had planned on but just wanted to hear the opinion of some ls1 people before I went and did anything. Thanks again.

 

A tune is where id start . Before you go get a tune maybe think about changing the plugs and wire and fuel filter.

 

It sounds like a tuning issue. The backfire could be a lean pop on hard acceleration. I would start with a tune and go from there. Stay away from a mail order tune because you need someone to look at the car because you do not know what cam, ect. that you have in the engine. Hopefully that is all it is. good luck.

 

Just did some peaking under the hood... looks like I have 317 heads and the cam cover looks like it has been recently opened and possibly replaced leading me to believe there IS a better can in there. The 317s seem to be good for boost which is where I wanted to go anyway. For now though I'll take it in for a good custom dyno tune. Thanks for the reply. Any other thoughts would be appreciated.

 

Before you go boosted, your going to want to pull a head and check if they have been milled. It was a trend years ago to mill the crap out of 317 heads to make a cheep 243/799 head alternative for N/A applications.

 

People. He doesn't want to hear it's a tuning issue. Let it go.....

 

On the contrary, read my posts. I have said more than once I'm getting it tuned. Ive been reading alot and after i get the tune sorted I plan to drive it daily like that while I begin to build a stout boost friendly lq4 based engine to drop in once I have the rest of the drive train and suspension ready to handle the power. In a nutshell it will be fun once the whole car is setup. I am thinking some data logging is in order especially after the discovery of the 317's.

 

Id start by doing what your doing. Replaced the front 02 sensors already. Check for vaccum leaks to the best of your ability. Id put a set of plugs and wires on it and a fuel filter.Make sure the air filter is good. After you are sure everything is in order go see your tuner of choice. Just don't bring him a car with all the old filters and plugs and such.Doing so waste time and money and its best to bring him a car that is up to the task of getting tuned and not all run down and not knowing what kinda shape everything is in. Just do your basic tune up stuff yourself.

 

I also failed to mention I gave it brand new OEM ac delco plugs and a new fuel filter as well. The first thing I did was give it a good tune up when it started to throw codes andmmiss fire. I also did a good vacuum leak test and found nothing. It idles at a very solid 600 rpms but the car rocks around some as though the cam is loping. I am just about to throw a 3-4 clutch pack in my gmt800 and the t/a won't be driven until its tuned. I am serious about the boosted lq engine. It will be my first boosted v8 but not my first build. Thanks for the advice.

 

First off... a 1 minute burnout?... there is no reason to ever do that unless you are trying to waste tires and draw the attention of the cops

Telling us what cars you beat racing doesnt help us know what has been done to the car....in order to diagnose a problem, we have to know mechanical details..Mods, Tuning, DTC Codes(actual #'s of the codes, not just "its an o2 code...there are multiple of them and each means a different thing.
henceforth what this smilie was designed for......

it sounds like the car has mods.....and its unknown if the car is tuned or has a stock file in the pcm....
so first thing you should do is go to a tuner, have them read the file, and have them look at it and tell you if its stock, or if it has been modified.
this can tell you a whole wealth of info...




Big words for a 2nd post on the forum.....
the worthless person appears to be calling the kettle black with their lack of knowledge of how to express themselves in a way that is not derogatory.
Old Geezer may not have goven a great response, or the one you were looking for...but no need to say it was a worthless post....
but he is right...you need to post in the PCM and Tuning section with Data logs and Tune file .....
though with a user name like old geezer... I would expect a little sass in a reply..LOL



the bank 2 o2 code is nothing to worry about...it is the code for a catalyst that isnt working, or isnt there....or its a badrear o2 sensor
that rear o2 sensor doesnt do anything to the fueling...all it does is monitor if the catalyst is doing its job properly....and tells you when to replace the cat's when they go bad... thats it...emissions related only

once again, for somebody who only has a few posts on here, you are going around calling people an *******??
I'm telling you now...you need to change your attitude
he made a suggestion... you can choose to ignore it...
he suggested going to a tuner......I suggest the same thing...go see a tuner and have them look at the file in the pcm...............

suddenly the advice about going to a tuner is valid???? after calling people ******** and tellling them their posts are worthless....




thats what I took from his posts

really...so suddenly after a reputable shop suggest going to a tuner, LilJayV10's post is now valid? after you already called him an *******?


unfortunately, you may have been pissing in the wind with new plugs...
if the tune is off(lets say its rich), they will only help for a short time before they foul out just like what was already in there...


the car idling at 600.....with a cam...is too low of an idle rpm....probably needs to be up around 800 or 850 for the cam at the low point...not saying its a must do....but it will help keep the plugs cleaner at idle if it has a few more rpm and it will have less chance of throwing misfire codes because its easier to hold a steady rpm with a cam at higher rpms(600 rpm is a lot of load for an engine to keep stead at with a cam.....)


and realistically.... the dealer possibly bought the car in an auction from a repo....and somebody may have flashed a stock tune to a modded car...in which case......if the cam was a smaller one (less than a 224/224), it might drive reasonably well with a stock tune...hell I know guys that have thrown in a hotcam, and done nothing to the tune and its just fine...not ideal...but its runs and drives with stock street manners.

so like I already said.... go find a tuner....find out what has been done in the pcm, and have a tuner decide if it needs some adjustment in the tune, or if its a mechanical issue causing the problems you are seeing



now...... I wasnt trying to be an ******* with this post...but I was purposely being a little rude to show you that some of your responses were uncalled for and that you can choose to respond differently.....I know I would appreciate it as would others...






p.s.......
please stop doing 1 minute burnouts unless you are at a burnout competition...
you are making the rest of us responsible Hot rod owners look bad.