1128 and 1130 still... Idle is HORRIBLE

[MN 986]

Have you considered the AOS? I had the same codes recently and similar idle bouncing, and while I did not necessarily hear chirping, I have read that a failing AOS can make some odd noises. Mine actually made a light hissing sound when the car was warmed up. Check it by trying to remove the oil filler cap while idling. Difficult to impossible to remove indicates a failing AOS. I was amazed at the difference with the new AOS,,, the cap comes right off. I think my AOS was failing for a long time, but it started to smoke upon starting regularly about the time the idle bounce started. It all was resolved with the new AOS.
Good luck.

[jcb986]

My understanding is that O2 Sensors do not cause an engine to hesitate or idle roughly. Just disconnect one and see the difference for yourself. If you can or have someone with an extra coil pack, try changing one coil pack at a time and see if it is one of them. You can also clean the throttle body. There is a cam sensor that could be going bad and of course a vacuum leak, which is the hardest one to find. Now lets think inside the engine and what could cause the problem. One is a burnt value or a cam lobe that has worn down enough to cause the problem by not allowing the valve to open enough.

[ProjectM96]

O2 sensors could cause the engine to hesitate while accelerating.

Coils could definitely cause rough idle and misfire.
I would replace the coils, which should be replaced everytime you do a tune up.

[Topless]

Intake and exhaust leaks need to be fixed and your idle will smooth out. The codes listed are common for intake or exhaust leaks. The car is running lean.

[shadrach74]

Originally Posted by Topless

Intake and exhaust leaks need to be fixed and your idle will smooth out. The codes listed are common for intake or exhaust leaks. The car is running lean.

How does the ECU read an exhaust leak aft of the post cat O2 sensor? It seems to me that anything from that point back makes no difference to the ECU. If id does,please help me understand how leaky bypass pipes cause idling issues?

[BYprodriver]

Originally Posted by shadrach74

How does the ECU read an exhaust leak aft of the post cat O2 sensor? It seems to me that anything from that point back makes no difference to the ECU. If id does,please help me understand how leaky bypass pipes cause idling issues?

The ECU reads that the engine is running lean beyond the ECU's capability to compenstate. Exhaust leaks is 1 of many possible causes.

[shadrach74]

Originally Posted by BYprodriver

The ECU reads that the engine is running lean beyond the ECU's capability to compenstate. Exhaust leaks is 1 of many possible causes.

How does the engine read a "lean run" condition from a leak aft of the metered section of exhaust? There is no O2 sensor on the mid-pipe/secondary cat. The only leak the ECU would have the ability to detect would be between where the manifold meets the exhaust port or an actual hole in the manifold/header. I cannot understand your assertion that the O2 sensors are capable of sensing anything downstream of their positions...

[BYprodriver]

Originally Posted by ProjectM96

O2 sensors could cause the engine to hesitate while accelerating.

Coils could definitely cause rough idle and misfire.
I would replace the coils, which should be replaced everytime you do a tune up.

My 2000 S with 102,K miles has the original coils. If they misfire it lights the CEL.