I had my buddy run the check engine light codes and this was one of them along w/ all 4 O2 sensors. it is PO734 Incorrect Gear Ratio (4)????? it runs fine and shifts fine so have no idea what would cause this...

Thanks
David

 

I had that with 2 other codes (don't remember the numbers off hand) but they were "bank 1 too lean" and "bank 2 too lean". Had to replace the MAF on my D2. When I was telling my mechanic about the codes it wasn't until I told him about the Gear 4 Ratio code that he knew I needed a new MAF. It might be something different for you though.

 

Most likelyan air metering problem. Check for vacuum leaks too. I had that code off and on for months, eventually it came on all the time along with those 2 lean codes and a 3rd gear ratio code as well. Well, I think I finally foundthe problem and it wasn't the MAF like I thought. There is a plastic nipple that threads into the passenger side of the intake with a hose attached running to the valve cover which had loosened up. I put some teflon thread tape on there and I've been code free for almost a week. Damn thing better not come back.

 

Hi jkid,

Will you be able to post a photo of the plastic nipple? I am not sure where to look.

Thanks in advance!

 

Give us all the exact codes along with the mileage on your truck.