car loops idle up and down when gas is let go

[Lalaland]

Originally Posted by rb25crazy

bad lambda sensor? is that the o2 sensor? i changed mine back like 10k miles ago. im assuming its still good unless... i got unlucky with a new one.

Yes, the O2 sensor But since you've got a fairly new one i probably would listen to these other guys, regarding the vacuum leaks an so on. You never know with sensors but i doubt you are that unlucky.

For the electrical tests i would set your multimeter to Ohm, and measure your temperature sensor directly without the connector in, note the reading on your meter, reconnect the plug. Then i would measure the same thing on your main connector on ECU, measuring between the signal wire and ground on ECU, not the chassis or elsewhere. The value should not change notably. If it does you have a bad wire or connector somewhere in between.

Probably not the most helpful information, but systematic troubleshooting is the route to go.