calistang05

Bare with me this will be long. So last Saturday I take like a 200 mile drive and as I get off the freeway going home I notice my temp. Gauge needle starts going to the red but stops between the middle and red of the gauge. So I get home check everything no leaks, no steam, no smell, fans working, so I turn off the car and the needle goes to the middle and stops does not drop to cold. So I start the car and it goes all the way red. WTF so I let it cool off for five or more hours so I check the gauge needle and it still in the middle. Turn the key to on position it goes to the red. So next morning I turn the key to on the needle moves to red then goes towards the cold stops midway, I do this on/off with the ignition 3-4 more times and it goes all the way back to cold. Never started the car to let it warm up so next I let it warm up to see we're the needle stop, so it's warmed up now and the needle stay in the middle like normal. Not overheating great! But then I look and now the check engine lights on. WTF, so I hook up the sct tuner and pulls a code P2198 02 sensor stuck bank 2 rich. So read up on it need to change sensors I guess, so I have smog check coming in October so I put my stock air cleaner back on and change back to the stock tune and now there is no check engine light. So does anybody think that the 91 octane tune I was running is bad now even though I been driving with no problems for the last five years. On a side note I had my car in paint shop for 3 months in which the battery was disconnected would that do anything to the tune? Should I just drive my car on the stock tune for while and see if the dummy lights come on? Also after it warmed up I could hear my coolant cap making a little hissing noise probably a bad seal need to get a new one. Car has 85,000 miles with JLT CAI 91 octane tune with bbk short headers. Thanks for any info and help.

steel pony

It's quite possible that the stepper motor on the guage is going, or you have an intermittent thermostat issue.

The reason your CEL went off is that when you flash the car, it clears and resets the ECM. Drive the car for 50 miles and you'll know if the CEL code is real (which i suspect it is) or not. It will return in time if it's actually tripping something, so this is a good test to ensure it's reading the same code or different/multiple issues.

calistang05

Thanks, steel pony so if the code comes back then it has to be the front o2 sensors that are brunt up from running the 91 octane tune right? Or is there something else code p2198 can mean something else can be wrong?

steel pony

70k-80k range tends to be the life expectancy for some of the parts on these cars. Not uncommon for the O2 sensors to burn out. I doubt it has anything to do with the tune, unless you have been running too rich or too lean for too long, but that doesn't seem like the issue due to your 5yrs of "no trouble".
It's just time...replace them if needed and address any other codes that come up prior to inspection