Service Engine Light after new tires/wheels?
 

I've searched the site and came up with less than nothing...

I had new wheels/tires installed today, and as soon as I drove out of the tire center, I noticed the service engine soon light came on. They were closing so it was too late to go back.

FYI... I went from OEM 18" wheels/tires, to 20" wheels and 305/30 rear, 255/35 fronts. I checked the diameters, and OEM are 27" front/26.7" rear diameter, new tires are 27.01" front/27.24" rear...

I assume its the differences in tire diameters, but I thought as long as the difference between front to rear was less than 0.3", I'd be fine... the fronts are almost identical to OEM, but of course the rears are a good bit taller than the OEM rears... but from front to rear, it's only 0.23" difference...

Can I fix this without having to buy new tires? Will it harm anything long term to leave it as is?

Check the code, I cant find a reason that the SES light would go off because of drive train changes.. Could be as simple as the gas cap

Any local auto store should be able to read it (AutoZone for free)

My 05 Dodge 2500 diesel threw a code once...found out that U turn the key to ON 3 times and it shows the code on the odometer, pretty cool.

Turns out it was because of my high flow catalytic converters, just seemed really weird to have come on weeks after those were installed, but immediately after the new tires were!