Got an 88 Mercury Grand Marquis with an EFI 302. When you let off the accelerator (coasting to a stop and such) it dies.

The codes i got:
KOEO:54- Mid temperature switch is open constantly
82- Air diverter solenoid circuit fault

KOER: 91- O2 sensor always lean


I have no idea what the two KOEO codes mean. I'm sure it needs a tuneup, but could that be all that it needs?

Help please....this is my sisters car...

 

I don`t even know what a mid-temp switch is but the first thing I would do, is pull the EGR valve vacuum pipe, plug it and see if that helps.

 

Ill try that.

Is the air diverter solenoid like an IAC valve? Does it need cleaned or something?

 

The IAC valve has about six different names but never heard it called that, so I don`t know. I thought it was maybe the smog pump controller.

 

Air diverter solenoid could be "Stuck" open and allowing for fresh air to be continously pumped into the exhaust giving you the "O2 Always Lean". I have had several problems in the past and I ended up getting both the Thermactor Air Diverter and Air Bypass solenoids from my the Dealer.

If you do a search for those terms, TAD, TAB, Thermactor, you will find more info. I know RLA2005, Subford and myself have covered this.

Hope this helps.

 

I'll do that then...