KB99WS6

iTrader: (6)

Just got back from a shop that installed Dynatech Supermaxx LT's on my '01 Z06. It seemed ok after we started it up in the shop and when i first started driving, but I was barely driving b/c this is in the middle of queens and all little streets. After a few minutes and when I get more in the open, all the sudden it like barely wanted to go. Seems and even sounds like its running on one cylinder when I was rying to give it gas (in any gear), but than out of no where, it will suddenly kick in and throw you back. It will idle fine too, its just under load it chugs along and barely wants to move, but than like i said at times will kick in fully, until I let off the peddle a a bit and than back to chugging along. Did this back and forth routine the whole hour ride home.

One thing is the headers were used and apparently there was no 02 extensions in the box of stuff I had. But he said he was still able to reach them far enough and connect them. Also the car has not been dynotuned yet and the check engine light of course is on and blinking.

Any idea's?

stangkiller2005

iTrader: (15)

a blinking SES light is a missfire!

maybe they didnt plug in one of your spark plug wires correct?

94'BLKBRD

iTrader: (76)

make sure the spark plug wires are all the way in

MdFormula350

iTrader: (4)

check wires, check coil pack connections in the middle of each side of the pack.
seems like an ignition problem.

KB99WS6

iTrader: (6)

Ok, I checked all the plug wires and everything looks fine. here's the strange part, I took it for a ride and it ran perfect for the first minute, than it went right back to barely running again.

The check engine light stayed fully lit the whole time, it never blinked. On my way home from the shop it wasn't blinking the whole time only occasionally.

I didn't check the coil pack connections and mind you I am no mechanic. But it just seems like too big of a coincidence that the ignition went bad at the same exact time I had the LT's installed. I would assume it's something that happened with the install...

Could the O2's have anything to do with this? is this likely just an issue with a fouled plug or something?

sunsetta

iTrader: (3)

Get under the car and look to see that all the O2 sensor connections are tight and make sure that none of the wires are not touching one of the headers, which could have melted the insulation off the wire and possibly causing an intermitent connection.

blkZ28spt

Triple check the plug wires at the plugs and the coil packs. Most problems after a header swap come back to loose wires. When snapping them on to the coil packs (I think it's the coil pack side of the wire, been awhile since I removed mine) it clicks TWICE before it is on all the way. I would unplug them and then push them back on until you hear two clicks.

The coil packs themselves also connect to other parts, obviously. Check those connections a stated above.

Also check the O2s. The fact that it was good and then went bad while driving makes me think it could be an O2 problem. When the car is cool it runs in a closed loop (not using O2 sensor feedback) but once it warms up it uses the O2 feedback...BUT as mentioned blinking is a missfire which is an ignition issue...

mvvette97

iTrader: (18)

They may of cracked one of the spark plugs. You said he didn't use any extensions for the O2s? On my vette there was no way to get them hooked up without them.

blkZ28spt

I missed this the first time through, reading in a hurry.

That may be your problem. You need extensions. Proper extensions. I don't know how they got connected without them...might want to take a look at that!

KB99WS6

iTrader: (6)

Thanks for everyones input!

I really think it's the 02 sensors because I checked all the plug wires and they all look fine. Plus, since I didn't have the 02 extensions and he was struggling under the car for a while to get them to reach, I assumed something happened there. Furthermore, that is exactly whats happening, is the car runs fine at first when its cold and than once it gets warm up its starts barely running.

The only confusing thing is why I got a blinking check engine light which means a misfire. Is the 02 problem be causing the misfiring? I certainly would think so, b/c again it seems like its running on 1 or 2 cylinders when it gets warm.

blkZ28spt

You could very easily have a loose connection with one of the plug wires and the O2 problem. Triple check all of the plug/wire connections and get some proper O2 extensions as a first step.

I would be interested to see the O2 sensors and their wiring as they are right now...

MdFormula350

iTrader: (4)

i am pretty sure the ses light can come on for a o2 sensor. sounds like the car runs fun in the beginning when cold because its in open loop, and whens it start to warm up the comptuer switches over to closed loop and the ***** hits the fan because o2's are not reading right at all.


definitely look over ur o2 wiring, I am suprised a shop would try and route it as since its a stretch using stock wiring and o2's, at least on fbodies.

stangkiller2005

iTrader: (15)

yea it has to be o2s because it dosnt do it in open loop. due to the car putting out more gas.. but in closed loop o2s arnt working properly, and making car nut run correctly aswell...i thought vettes had longer 02 wires tho.. so they didnt need extentions.. cuz i kno people told me to get vette o2s instead of extensions..cuz they were longer. then stock o2s for f-bodys and ran hotter or something like that..

blkZ28spt

Vette O2s have longer wires because the sensors on the Y-body are further back.

They are also designed to function properly further downstream within the exhaust, where it is cooler.

That is what you are thinking of.

silverbandit0996

iTrader: (2)

make sure the coolant temp sensor is plugged in.

tuffass

Had this exaact sameprob when I installed mine. It's your 02's. I'd suggest getting a tune too after you replace them. I didnt get a tune and my air/fuel mixture kept getting worse and worse...

staringback05

iTrader: (8)

also make sure your o2 wires arent arching off of something....ive seen this before...

greatskiiiier

iTrader: (10)

I didn't read the other posts, but this is the same exact problem I had... take off the batt. unplug and replug 02 extensions and 02 sims, should fix it until you get a tune... mine still bogs randomly,and idles high... waiting on tune

also make sure all wires are plugged in fully, and no wires and arcing on the headers

Luna

iTrader: (6)

I think its your coolant temp sensor. How is it on a hot start? If it stumbles and runs like crap on a hot start this is most likely your problem. If not keep looking. Double check the connection to that. A new one is cheap if thats the problem.

01FormulaTA

iTrader: (20)

it is your o2's for sure, get the bosch 13111's immediately, a blinking SES light means a cylinder(s) isnt firing correctly(your'e car is missing), also check your spark plug wires