My daughter's MCS has been down on power for about a week. It threw a code when I was driving it but later cleared. Yesterday, she was at a stop light and the RPMs rose to around 1200, the CEL came on, then the RPM returned to normal idle speed. Today, she drove it (in the 30's here this a.m.) and told me it "rattled" at some some point while she was driving (didn't notice it when she cranked it or when she drove it home).

Thus far I haven't heard it "rattle", I'll crank it before I go to work in the morning and give it a good listen. I did hear a little noise from the timing chain area when I cranked it a few minutes ago (it's been sitting all day) but it quieted down quickly. It also had an erratic idle at one point and actually "stumbled" before returning to a normal idle.

Car has about 66k miles, btw. Codes were B2AAA-Body P000A - Powertrain, P0130 - Powertrain 02 Sensor Circuit (Bank 1 Sensor 1) and P2243 - Powertrain - O2 Sensor Reference Voltage Circuit/Open Bank 1 Sensor 1 Codes are currently cleared but I haven't driven it again yet.

So.....will a sloppy timing chain throw the P000A code?
Should I just replace the sensor and see what it does?
Am I more likely looking at a chain replacement job?

Thank you.
Richard

 

 

Thank you for the info and the link.

 

Small update. I drove it today. No issues. Scanner says the 2 previously mentioned codes related to O2 sensor bank1 sensor 1 are "pending". New O2 sensor will be here tomorrow, we'll see what that does for her and I'll post back with the results.