1999 Toyota Tacoma Q&A
1999 Toyota Tacoma Question: p0300,p0303,p0304 trouble codes come on after engine warms up.
In the mornings when I first get going, no codes, everything works great. then the codes kick in when engine is good and warm and accelerating. If it is a very cool morning, it wont happen. I have changed everything under the hood and had a very good import shop look at it. They think maybe a small coolant leak starts after warmup. But I have a v6 and and cyc 3 and 4 on different sides. Any thoughts??? - jody4599
YOU MAY HAVE A CRACKS IN YOUR CYL HEADS THAT DO OPEN AFTER WARM. IS YOUR OIL MILKY IF NOT CK YOUR COOLING SYSTEM FOR EXH GASES - globalhelper
Have a simple chemical test known as a block test done see if you have a blown head gasket. Perhaps change the spark plugs, check compression is even, your engine has SHIM adjusted valves seen the clearance get tight on higher mileage engine and set misfire code like you say. Check for vacuum leaks, maybe a fuel injector issue. - patrick mannion