Took the car out today,drove about 50 miles and noticed the engine sputtering,almost like a vapor lock,drove another 30 or so miles and it kept sputtering,so I finally decided to pull over and check things, noticed the chrome tail pipes were covered in black soot,checked under the hood did not see anything obvious,so as I was heading home I stopped to get more gas,thinking maybe new gas would help,well when I left the gas station the car seemed fine,is it possible that maybe the gas cap was the problem and when I removed it maybe something got fixed.Any help would be appreciated.
Car is a 99 vert,six speed,aps twin turbo with heads and came,running 7 lbs of boost.

 

On these cars it could be anything. Check your DIC for PCM codes. I've had alot of these issues just with small things like plugs, wires, MAF, O2 sensors, ect....

 

I checked and pulled P0103 H C

 

Ok that is a start. The code is Mass Air Flow (MAF) Circuit High Input. Here is a link to trouble shoot it. If you are still having trouble tomarrow I can look up these codes in my manual and point you in a better direction .


This one I googled
http://www.obd-codes.com/trouble_cod...high-input.php

 

Well I checked the car this morning and noticed that it had a light layer of powder soot on the car and on the floor,this is from when I started the car last night to pull the codes,anyway I checked all the wires and found nothing wrong,so I decided to remove one of the plugs to see what it looked like,on the driver side the plugs were dry and a rustic color,on the passenger side,the plugs were black carbon color,so I'm curious about why they are different,anyway I went ahead and put all new plugs in the car and started it up,the car sounds very good,but like I was saying yesterday the car seemed ok after I put more gas in it.
So I'm still not sure until I drive it some distance whether or not it is ok. I have tried to reset the code[P0103],but am unable to do so.I am wondering why there is so much exhaust soot,could this be coming from a trouble with my turbos,these turbos are fairly new,less than 2000 miles on them,Im hoping that they are performing as promised,so if anyone has any idea what could be causing this all of a sudden,please speak up.Like I was saying,the car started cutting out but when I would punch it,it seemed to be ok and at certain rpm it would start sputtering and cutting out.

 

You have to hold down the reset button for a couple of seconds for the code to reset. The plugs have black carbon on them because of the misfire. I would try to take your coupler off both sides of the MAF sensor and tighten it down alittle. If you tighten down to much it could throw a code. I hope this helps .

 

Hi Donny,

You have the P0103 because you have a HP Tuners 2 bar speed density tune. If you did not have the code the car would not run in speed density mode.

Not exactly sure why one bank was running richer than the other though. O2 sensor would be my primary suspect though.

 

O2's are cheap. For one bank to be rich when the other isnt, got to be the O2 or teh connector. BTW, O2's will last a long time until they are run rich once too often.

 

I'm not to familiar with the 02 sensors,would I need to replace all 4 sensors.

 

Let me try again,since I am running no cats with my aps,the back sensors were probably deleted,so would I need to replace both front 02's?
Thanks,Donnie

 

I would replace the o2 sensor on the passenger side since the plugs on that side looked black.