can't drive 55

i know this is a ls1 website but i liked your helpfulness in the past on my 1997 ss, and i was wondering if you could help me again. My car has some mods but nothing to in depth. ( Flowmaster exhaust w/BBk longtube headers, 52 mm throttle body, 410 rearend, and a different thermostat, it also has some different coils, that i believe help with a hotter spark.) The problem: i noticed in the last couple of months that when i am going down the road my car has a tendency to have a kickback. (usually on the low end or mid range gears, 1-4) Like it is cutting out, i also noticed that very recently, right after i start it, if i let it sit on its own without me doing anything, that the idle will go down to around 600 or 700 rpm, within a few seconds of starting it and then it will die on me. thanks for any help!

monodax

Is your opti-spark fairly new? plugs? wires? intake tear?

can't drive 55

i bought the car about four months ago and the guy had already put everything in so i'm not sure on the newness of everything, but i also failed to mention that i have an exhaust leak of some kind, whether it be the header bolts, or where the headers meet the exhaust. Would this possibly cause the kickback, or the cutting out problem? thanks for the feedback

monodax

If the leak is before the O2 sensors it could be causing issues as your O2 sensors need a non contaminated exhaust to operate correctly. You could have oxygen getting in to your exhaust from your leak and causing a lean condition. You can tell easily if you hook up any type of scanner to your OBDII port like AutoTap and measure the left side O2 against the right side and if their is a significant difference in their readings then that's your problem.

BTW, When your car kicksback or cutsout does the SES light flash?

can't drive 55

hi, i have a quick update, i did some checking with a computer module that i have, and one of my o2 sensors is acting up, and also i noticed that right after starting my car that without touching anything my car has a tendency to change in idle speeds varying from 600 to 1300 rpm's, and it now has the kickback or cutting out sensation throughout all of the gears also. and i also noticed that my (service engine soon) light has been either disconnected, or impared in some way, if i could get that hooked back up it would help a lot. if you have any feedback on the information i would really appreciate it. thanks

S8ER95Z

iTrader: (3)

Hmm..hows the EGR? I had the tube between intake and the manifold break.. It was acting very funny as well... never died on me though.

monodax

Some shady dealerships I know in the past have disconnected the Check Engine lights in cars when they are illuminated when they get the car from an auction. Generally when something they don't want the customer to know about is broken. I always check when I start a car to see how many of the lights illuminate just as a reference.

can't drive 55

the car has always been privately owned, and help me out here (EGR) is what again, by knowing this it might lead to knowing whats wrong. thanks for the feedback and any more you might have.

S8ER95Z

iTrader: (3)

The egr is on the back of the intake... there is a valve that allows unburnt gasses from the exhaust to recirculate into the intake. Then there is a metal tube that connects between the exhaust and the intake. Facing from the front of the car, the left side is the tube and the right side is the valve.

can't drive 55

So i know that one of my o2 sensors is bad for sure, and then what if i found out that the egr valve was bad also, would these two together cause a cutting out of the car through the gears and also when it is idleing. Also can you tell that the egr valve is bad by hooking up a scanner to the car, and on estimate what would the cost be for a new o2 sensor and egr valve be, and how much labor would be involved in getting the new ones put in. i sure wish i could put them in myself, but until i learn more, i'll have to just help the mechanic for now. thanks for any feedback

CaptUSA

iTrader: (5)

I can't speek for the LT1, but I just had my EGR tube replaced (under warrantee), and the bill said it was over $800! I thought that was crazy (wasn't too hot since I wasn't paying for it), so I asked why that was so expensive. The mech told me you have to rip half the engine appart to get down the the back of it. If I were you, I'd shop around the reginal section, and track down a buddy who could help you out. The O2 sensor shouldn't be too bad though. Good luck to you. Hope it all works out okay.

S8ER95Z

iTrader: (3)

Enh, EGR rube itself isnt hard to reach at all, and the valve isn't really difficult either on the LT1. (its in a diferent location completely on the LS1) technically all you have to do to test the egr is manually apply vaccum or push on the diaphram and see how the car reacts. The tube itself, its either leaking or not there at all. Otherwise it should be fine. Just trying to think of different problems I have had. A clogged Cat will cause issues too.

can't drive 55

ok i'm pretty sure that i found the tube that connects the intake to the exhaust. but i'm not sure if i found the valve or not. is the valve a black circular shape, because what i found is right behind the intake and it is right in the middle, not on the right side.