My car has a P0300 engine code. Spark plugs, wires etc are fine. My dad took off the vacuum tube for the EGR and put it back on. My car does not have a rough idle anymore so we reset the computer code. Have driven about 10 miles and the light has not come on and it is still running smoothly. How much more should I drive before taking it to get smogged?
SOURCE: 87 chevy 350 fuel injected pickup wont run smoothly
sounds like your egr valve is gummed up or bad. this is located behind the throttle body and has a single vaccum tube connected to it. if the diafram is still good you can remove it and clean it with WD 40 until the plunger works smooth
SOURCE: Rough idle code P0300
Did you upgrade spark plugs to a multispark or performance plug???? if so go and purchase original plug that vehicle calls for... This is what i would do, after all is back with original stuff including plugs I would disconnect the battery for a couple minutes and then try and start again. If same conditions and you get same code replace pressure regulator... Make sure you find out this is the code before purchase . I am almost positive that the code you have is for the fuel pressure regulator...Good Luck
SOURCE: Had EGR valve replaced 3 mos ago. Now I'm getting P0300 & P0404
Turns out they should have put in a new fuel pump rather than the EGR valve. Hopefully this will solve the problem.
SOURCE: I own a 2002 Chevy Trailblazer with 4200 vortec
Do you know if the plugs were changed, a bad or broken plug will also cause rough idle and slow acceleration?
SOURCE: i have a p0300 code and a p0404 code and i have
have a back pressure test run on the exhaust system..could be a restricted catalytic converter
A code P0300 may mean that one or more of the following has happened:
If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders ( spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.
Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open
156 views
Usually answered in minutes!
The plugs have been changed within the last year and are all working. The only thing we did yesterday when we reset the computer was that little hose disconnecting it from the EGR and my car runs very quiet now and it hasn't done that in a long time.
×