Mike Zarnock

Just like the heading says....
Is there anyone in Central NY that can fix a C4 with computer problems?
I live near Utica.

qws

Whats your problem with the computer?

Mike Zarnock

Here is what it was doing....

I was driving it with the wife one day all over town and the country side slowly and at low RPM’s. After a few hours of this we ended up in the city and had to stop for a light, when I stopped, it stalled and would not idle.
I got it home by keeping my foot on the pedal. When I started it, the dash would read "SYS".... and it ran rich, and the engine would not idle at all There were no codes..., just says “Service Engine Soon”, that is the freaky thing. Scan tool reads all is well on every point, fuel trim was on, timing was on, all was reading well….. That is what was throwing me. The manual said that the “SYS” meant that the CCM "Central Control Module” was bad and needed to be replaced. That’s why I was looking for info on replacing it.

My wife read in the manual about cleaning the Oxygen sensor when the engine was running like crap at idle….
It said to clean the o2 sensor by running the engine at 2 grand for 2 minutes. So…. to appease my wife, I did it and it fixed the problem. (Good thing!)

I guess I cannot drive the car slowly at low RPM for long periods of time. It must have started when I drove the car in a parade last summer and then never really cleaned it out....
I will be changing all the o2 sensors real soon!
Thanx for the help!
Mike

VETTEHIGH

Redline motorsports?

qws

I was just gonna suggest Redline. There in Schnectaday and theres a link in the banner section to the left. Hes good. I've had my car there.

tdr1919

try laoding up with some high test and a bottle of techtron, take it out to the thruway and run it at 60- 70 for a half our, you may need to replace the O2 sensors.

Mike Zarnock

I played with it today at 80 to 90 at about 3 to 5 grand and it cleared up a lot! I always use High Octane fuel, but last summer there was nothing but garbage here for fuel. And is probably why it loaded up at low RPMs.
I'm ordering all new o2 Sensors tomorrow as soon as I get to work!

Mike Zarnock

I'll have to check them out.... I go out that way a lot.
Thanx!

toptechx6

You posted two different symptoms, did it display SES or SYS? SYS will often display with a low battery, I would make sure yours has clean connections and is fully charged first, good luck.

Mike Zarnock

it was "SYS" and it would read across the dash while the engine was running rough. I also had the same "SYS" a couple years ago when the ECM went bad.
This car has many symptoms when it goes bad.... and never an easy fix!

corvette95

What year car? Optispark can cause all kinds of false codes.... thats where I would start

onedef92

What shape are your ignition wires in? Got more than 60,000 miles on 'em? A bad plug or coil wire can make these HEI-equipped cars shake, buck, and misfire like a ****, too.

Mike Zarnock

There were no codes....

Mike Zarnock

Everything is new.... wires, plugs, coil, cap, ignition module, ECM, Knock Sensor, EGR valve, and anything else that can be changed....