My car: 1998 Vert A4.

Have had it a couple times this summer, yesterday being the most recent.
Check engine light comes on. Car runs fine. Check the codes when I get home and have the following. P0171 & P0174, both being history.
Clear the codes and check engine light goes off. Start it up this morning, same codes, only one of them is showing current. Check engine light is on. Clear the codes and all is fine.

Is this something that I need to have checked out or need to be concerned with? If I remember correctly, they are basically to rich of fuel. Going on a 5 day trip late next week, so if I need to get it checked, I would want to do this right away before we leave.

Question 2: Friend of mine has a 2000 Vert, A4. Occasionally, he turns on the turn signal, left or right doesn't make a difference, and no flashing. I am behind him and when he applies the brake, whichever turn signal has activated, the tail lights or brake lights go out. I know when he has a problem as he would only have one brake light as the side that he has the turn signal activated, shows nothing. He can also tell as his turn signal indicators on the dash isn't flashing.

Is this likely a ground problem or something different.

To show how sporatic it is. Had it occure in July for maybe 10 miles. Hasn't had a problem for the rest of the summer. Yesterday, had it again for maybe 10-15 miles, then it was fine. Really hard to find where the problem lies, because it is working when he wants to check into it.

Thanks
Greg C5

 

Sorry can't help you with your codes. But your friends turn signal trouble sounds just like my 2000 vert had. I had to change the flasher and it fixed the trouble. Do a search and you should find a ton of stuff on the four way flasher on here, it is a Common problem.

 

Actually the opposite.
P0171 Fuel Trim System Lean Bank 1
P0174 Fuel Trim System Lean Bank 2
You may want to get this checked out as to why you are running lean.
Lean not good.
Could be some thing as simple as replacing a fuel filter.

 

What the website you go to to check the codes?

 

Well the forum
http://forums.corvetteforum.com/show...ighlight=c1214
and these
http://www.corvetteactioncenter.com/...+Trouble+Codes
http://www.corvetteactioncenter.com/...+Trouble+Codes
http://www.corvetteactioncenter.com/...+Trouble+Codes
http://www.corvetteactioncenter.com/...+Trouble+Codes
http://www.corvetteactioncenter.com/...+Trouble+Codes
http://www.corvetteactioncenter.com/...+Trouble+Codes
http://www.stengel.net/diccodes.htm
http://www.gearchatter.com/index.php
http://www.corvettedoctor.com/Code_Main.html

 

Did you change your cold air intake. I had the same codes when I went
from stock air box to a Halltech.

 

You need to check it out quick considering you live in Iowa.If you are running lean and a cold front comes in or any cold weather for that matter,you could mess up your engine.

 

Thanks for the responces.

But why would it send these codes so sporatically.

I mean, I had it once this year early on, and then now again yesterday.

If it was truly a big problem, why wouldn't it throw the codes more often.

Greg C5

 

You could always be running towards the lean side and not set codes. The few times the codes where set just meant you went way out of the value for lean condition. Fuel flow can affect this condition. Easiest solution change fuel filter.

Any MODS?

 

these are left and right cylinder banks running lean. usually indicates either air intake leak after MAF sensor or MAF sensor itself, sometimes associated with po102, po103. p.r.t. thermistors in MAF not sensing thermal differential of intake air. (no/low air flow) and reducing fuel to compensate for low air flow

 

True.
A vacuum leak any where could,but a faulty fuel system can aid in this problem also.
Would the codes not be more frequent if vacuum leak present?
After reaching operating temp it only takes about 10 min to determine the proper fuel trims.So if he is going over +23% which takes to set P0171 & P0174, shouldn't the code be every time he drives if he was to have a vacuum leak or faulty MAF?
I am still learning these cars so I am not trying to be an Ahole

 

but if the MAF is on it's way out it might not, the three elements in the MAF can over time become coated with fine dust particles that can affect the thermisters ability to determine intake air flow/temp. a fuel system failure will usually be dectected in the air ratio by the o2 sensors, and limit the air intake (rpm)to compensate for the lean mix. If the MAF voltage differential is off there is nothing to redetermine the air fuel mix in the intake. the o2 sensors will prevent it from running rich but not lean.