Taho jerking hard at speeds of 40/45 MPH. Got code of p0300 & p0420 & p0430. Got a basic tune up wires & spark plugs & just got new catalysts converters welded in on Sat and still having the same jerking and same codes. I know it's not the transmission cause I just got it rebuilt within the last year. I spent 500 over the weekend to get the cats welded in & I'm stuck..... PLEASE HELP
My car has 260000 miles.
My car has an automatic transmission.
Hello - the first task is to check problem codes to see if the P0300 (misfire) code is still present, or others. If so - which seems to be what your description indicates - you may have ignition coil, crankshaft/camshaft position sensor problems, or fuel delivery (pressure, injector) problems still. I recommend an engine misfire inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.
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