Codes indicate possible bad catalytic converter, but I already replaced it. Codes went off for a while after replacing, then came back on. Not sure if pertinent, but I know a bad cat can cause a bucking. So maybe something else is making the cat go bad or has similar codes? Misfire/ lean / etc
Anyway...
when coming out of a stop, car bucks at around 18- 20 mph. I can sometimes prevent it from happening by either accelerating slowly past that mark, or letting off the gas right before it then accelerating again.
If I have a long drive (2 hours+), sometimes it doesn't do it at all or as much after that for the rest of the day.
Doesn't usually buck when coming out of a stop and making a wide turn (like an intersection).
Doesn't usually do it if I slow down to go under 20, then accelerate again without actually stopping.
Thank you in advance for any help .
RepairPal Certified shops can diagnose and repair your 2005 Ford Taurus. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
p0420 and p0430 refer to the y-pipe mini-catalytic converters directly off the exhaust manifolds. Is this what was replaced or was it the main cat. converter? P0300 could be various things caused by failed mini-cats or a vacuum leak or other things. Need to know if 1 or all 3 cats were replaced?
Was listed as the front, but the guy who installed it said it was the whole thing (but I may have misunderstood him)
this is what I bought
http://www.ebay.com/itm/New-Catalytic-Converter-Front-Ford-Taurus-Mercury-Sable-2000-2005-5YR-WARRANTY-/370928630235?hash=item565d11b9db
Okay those are the fronts....let's consider this though. The fronts pass the exhaust through the y-pipe to the main cat. converter and out the tailpipe. If the same issue persists with the fronts changed then the exhaust is still restricted which means the remaining cat. the main. If it plugs the exhaust still gets backed to both mini cats. back to the engine as well causing misfire condition. So, the original solution is more than likely......the main cat. converter was the problem all along but triggered the mini cats. through the back pressure. :) Need to see if the main looks as new as the fronts.
P0300 Random Misfire p0420 catalytic system below threshold bank 1 p0430 catalytic system below threshold bank 2
p0420 and p0430 refer to the y-pipe mini-catalytic converters directly off the exhaust manifolds. Is this what was replaced or was it the main cat. converter? P0300 could be various things caused by failed mini-cats or a vacuum leak or other things. Need to know if 1 or all 3 cats were replaced?
Was listed as the front, but the guy who installed it said it was the whole thing (but I may have misunderstood him) this is what I bought http://www.ebay.com/itm/New-Catalytic-Converter-Front-Ford-Taurus-Mercury-Sable-2000-2005-5YR-WARRANTY-/370928630235?hash=item565d11b9db
Okay those are the fronts....let's consider this though. The fronts pass the exhaust through the y-pipe to the main cat. converter and out the tailpipe. If the same issue persists with the fronts changed then the exhaust is still restricted which means the remaining cat. the main. If it plugs the exhaust still gets backed to both mini cats. back to the engine as well causing misfire condition. So, the original solution is more than likely......the main cat. converter was the problem all along but triggered the mini cats. through the back pressure. :) Need to see if the main looks as new as the fronts.
ok...thanks..will check it out