For a while acelerating under light throttle is slow and the car will fall on its face. Right after startup it is perfect on acceleration. Once I get some speed and the RPMs pick up it runs awesome. After some time and fixing other problems the car has gotten alot better. I decided to check my codes and I am getting 13 (O2), 32-34. 32 if for EGR and I don't have that thing anymore and 33 and 34 are for the MAF wich I about a year ago and went ahead and replaced that one a couple of months back since it still had a warranty. It is a reman MAF too. Code 13 could be a sticking TPS too and the O2 is pretty new. What am I looking at to what could be the culprit. Timing, spark, and fuel pressure are good. The car runs a little smoother with the MAF unplugged and also as far as I can see all of the wires are in good shape.

 

Where do you live? The reason I ask is because on some climates that are generally higher inhumidity tend to create corrosion problems in the harness connections.

Something I tend to see from northern states and eastern states is that the computer harness is a little loose, allowing corrosion to form on the pin connections, causing a high resistance. That gives some funky codes.

For a code 13, that means that the O2 sensor is either open, shorted to power, or shorte to ground. Our cars do not performa a logic check on the O2 sensor circuit. If the trans has ever been out of the car, check the harness that crosses over the bellhousing at the engine near the firewall. Sometimes people pinch wires there when reinstalling the trans.

If you've replaced the MAF sensor twice and still get the same code, chances are that you don't actually have a problem with a MAF sensor. It's got to be somewhere in the wiring back to the ECM. Just because it "looks" good, it might not be making a good connection. I always check anthing electrical with a DVOM, not just a visual check.

 

I'm in the panhandle of FL. I have only looked at the harness in the engine bay. What I need to do is look under the dash at the PCM I suppose for anything. Is there anything that I can do to clean any connections like PB Blaster that won't mess up the electronics? I also checked the voltage of the TPS and it is normal and goes up and down at a steady pace without any jumping around.

 

yea, they make a wd-40 looking thing for electrical connections, it dries really fast. i used it and it works pretty well. should be near the wd-40 too. in a car parts store anyway.

 

Radio Shack should actually sell some stuff labeled "Electronics Cleaner"

That's what I use at work.

 

Thanks. I'll get some of that stuff and spray it in the sensor connections and let you guys know how it goes. Hopefully this might solve my problem. The problems started occureing slowly so this might explain it.

 

THATS the stuff i was talking about.

 

You're getting code 33 and 34? That means your maf voltage is high and low . It's usually one or the other so it's probably a connection problem.

 

I never got those codes before so I am glad that a code finally surfaced to atleast point me in some direction.

 

I bought some stuff and it helped alot. It still does it a little bit but when I get home I clean all of the sensor connections alot better.

 

The stuff helped then when I put it on the connections a little but now its back. Runs soooo much better without the MAF plugged in but will still stumble a little. What can it be besides the connection? Is there any kind of relay that I don't know about.

 

Check the Ground At the Thermostat housing! Make sure bolt threads, and terminal are shiny clean This is the most overlooked area on GM If that doesn't correct your problem, check vacuum. should be 7 Inches @ 2000 RPM

 

My vacuum should be good as I have already checked and fixed any leaks, but then again my idle is a little iffy. Sometimes it is smooth and other times it is barly idling, I'll check everything again. The ground that you are talking about is the one that goes to the firewall?

 

On The Thermostat Housing (where the upper Radiator Hose Connects to the Intake

 

I never knew that there was a ground there. I'll check it out as soon as I can and let you know.

 

I looked for a ground there but I did not see anything. No loose wires. I did notice that today my cars RPM will raise a few hundred then go back down at a steady pace. It doesn it in drive and park.

 

I had the same thing happen when the throttle position sensor went out on mine, check that.

 

You need to Clean the Grounds, not look at them. Take them apart and clean them wit a wire brush. As moisture wicks into the connection, the resulting corrosion actally separates the connection. If you are showing high and low voltage codes on the MAF sensor, it is most likely going to be the ECM Ground. would also explain the other code faults you are experiencing.

computer Grounds are black with a white stripe

 

Or, better Yet, Find someone that has a code scanner with Datastream capabilities. It'll save a LOT of time and aggrivation if you can see what each sensor is actually doing!