So my MIL light on the new max (actually old 97 with 126K on it) came on today. Used a OBDII scanner from the parts store to quickly check the codes on my lunch break from work. Came up with P0400 - EGR flow control and P0325 - Knock sensor.

Two reasons that I'm confused. One the P0400 code doesn't match up with the normal P0302 EGR code for a 4th gen. The other is that the max has great power and gas mileage, so I don't know if the knock sensor code is just a ghost code caused by the EGR issue or what.

Furthermore, last week my alternator and battery died and I replaced both. Never reset the ECU though and in the code thread it states that the EGR code can be thrown by having a weak or dead battery.

Anybody have any input on how I should handle this?? Anyone with knock sensor codes ever still have good power and gas mileage??

 

Nevermind the part about the codes not matching...I'm a retard...I didn't realize that the scanner code and the blink code are different....:P

 

Mine has kicked out a KS for about 6 monthes now (ghost light), and I still get 25mpg overall, with around 28-30mpg strictly highway driving (hit 500 miles in one tank). Check your KS with an ohmeter and go from there. I still haven't checked mine, but as long as I'm getting good gas mileage I don't really care.

As for the light, I'd reset your ECU, drive for a bit and see if it comes back. Check codes if it doesn't come back just to make sure.

 

I had this same problem, both KS and EGR (0302)..My issue was resloved ny replacing EGR solenoid valve.

 

so the knock sensor code went away when you replaced the EGR solenoid valve?

 

I would also like to know the answer to this.

 

KS is a ghost code. I'm pretty sure it comes up whenever something else does. I've hand mine come on with the Engine temp sensor, both 02s, ect... Now if you check your ECU and the KS comes up by itself, then its bad.