Weird Idling when stopped! (2000 Malibu)

Ok so I did a few modifications to my 2000 Malibu. I have a straight pipe, I took off the cat and resinator and slapped on a Fllowmaster Muffler and threw in a custom intake. This was put on about two years ago. About a year ago my car started to idle weird when I would stop at a red light. The RPM gauge is always going between 400-700 Rpm ,up and down, up and down, and you feel the car getting weaker everytime it goes lower, but never to a point where it stalled. I changed the EGR valve, replaced the PCV valve, Gas filter, spark plugs and wires, even tried the rear o2 sensor, but nothing seems to help it. Would having no cat be the caouse of this problem, or is it something else???? :banghead:

Any codes stored? Could be, MAF, TPS, IAC.

what do u mean by stored codes?? I had the scanner hooked up and it said something about a misfire??? im clueless to what that is

what do u mean by stored codes?? I had the scanner hooked up and it said something about a misfire??? im clueless to what that is

The codes should give u an idea of what the problem is. What were the codes that came up? The "maf" is the mass air flow sensor, the "tps" is the throttle position sensor, the "iac" is the idle air control. All of these components can in one way or another have an effect on idle quality and drivability. Check the codes again and tell us which ones exactly came up.

The codes should give u an idea of what the problem is. What were the codes that came up? The "maf" is the mass air flow sensor, the "tps" is the throttle position sensor, the "iac" is the idle air control. All of these components can in one way or another have an effect on idle quality and drivability. Check the codes again and tell us which ones exactly came up.

None of those codes came up, and the Mass Air Flow Sensor was replaced which did nothing for me. Another thing however.....before these problems started I purchased one of those +5 HP chips that required me to snip the wires that connect into the MAF sensor, but I took the chip out shortly after, and tied the wires back together. Could this result from the wires having a tied flow, rather than a straight flow??

It sounds like the IAC to me.
Rob

None of those codes came up, and the Mass Air Flow Sensor was replaced which did nothing for me. Another thing however.....before these problems started I purchased one of those +5 HP chips that required me to snip the wires that connect into the MAF sensor, but I took the chip out shortly after, and tied the wires back together. Could this result from the wires having a tied flow, rather than a straight flow??

First thing I would do is "untie" the wires, slide a section of heat-shrink tubing over the wire and solder the connection well, then slide the heat-shrink over the union and heat it. Then cover the heat-shrink with electrical tape. Even if this isn't your problem; it would prevent an accidental ground, or electrical noise from two pieces of wire rubbing constantly when the engine flexes on her mounts.