Verified answer

P0734 Means incorrect 4th gear ratio. (or tcc problem). (tcc means torque converter clutch) your car has a shifting problem. It is not shifting into overdrive, (or lock up) you can take it to a local mechanic, try having your transmission serviced. If that does not cure your problem, you may need a tcc solenoid replacement.

P0734 - gear ratio 4 incorrect

You can try having the transmission serviced, but the long and short of it is that you probably have internal transmission problems ... Sorry I know you don't wanna hear this around the holidays, but ratio error codes are usually due to a clutch pack that's starting to slip .... It doesn't take much slipping before they're toast too!

Don't keep driving it until you have an HONEST transmission shop check it for you .... Seriously, a shop that is known for their honesty and good pricing will not screw you (my friend owns a trans shop and he is known for these qualities). ... Watch out for cottmans and other national chain shops...just sayin

First check the OBD Book and find out what po734 is referring to. The book has the description of the system and/or devices the code number is referring to.

If it's a transmission code...bad news if you don't know what you're doing. Generally speaking, if you haven't touched a transmission before you shouldn't. If you still have your factory warranty look into some dealership service for this problem.

my reasearch is telling me that your 4th gear in your tranmission is having trouble and should take it to the dealer. Im the last one to send any one to the dealer for repairs, due to cost , but this would be safest.