Car wont go over 3500 rpms

3.4l!

Check engine light on? Tuned it up lately? If it bogs when you floor it the problem could be a plugged up catalytic converter.

Check engine flashes if i hokd 3500 rpmsdoes bog when florred when florred still wont go past 3500 will hold there tune up recent

Try to read the trouble codes to see if any are pending or stored. You can try a fuel system cleaner and catalytic converter cleaner in the gas. No guarantees!

Do have some intermintent codes p0300 wich is misfire but not really sure where to go from there only paid 500 for car just trying to get trough the winter

A generic misfire code could at lot of things. Look it up on the web. A misfire will kill your cats!