Will a faulty check valve turn the check engine light on in my 1999 chevy suburban?

SOURCE: 200 Chevy Suburban -- trouble starting

Bad fuel pressure regulator. Located on drivers side of engine on fuel rail. Cost of part is around $70. Easy to replace. Buy the part, look at it, find the old one on the engine in the area described above. Pull the vacuum line off of it, if you see any fuel in the vacuum line it's bad. The vacuum line sucks up the fuel flooding the engine. Classic symptoms. Make sure to relieve the fuel pressure prior to removing or let it sit for a couple of hours, or over night. The leak will relieve the pressure over time. Simple clip holds it on, easy to get at. Make sure to remove both "O" rings prior to putting new unit on. Should solve the problem.

SOURCE: Would faulty EGR valve cause check engine light to come on?

If EGR was out your engine light would stay on!usually hi way drive is a whole new emission game sensor work 100% different that city drive you have a O2 sensor problem don"t Get$$ the problem when if you say it only will do it on highway then take it on highway with OBD 2 in run scan mode have a passenger observe it this will give the the proper code you will need to peg it cheers!

SOURCE: how to replace EGR valve on 99 Chevy Tracker

Take off your EGR valve and clean it out with carb cleaner also
grease tyhe little screw thing in it,,, u will c what i mean if u take it apart. carbon builds up in the chamber. it is located at the back left side of your engine and is a bit of a pain to take off. this should save u the cost except for the cleaner and labor. i had the same problem cheapest i found was 90$ on ebay.

SOURCE: 1999 chevy suburban misfire

could be one of several things
1) run a compression check, if it low on that cyl then you have a blown head gasket or burnt valve
2) could be the enjector

SOURCE: I have a 2002 Chevy

Basically this means that the the car's computer has detected that not all of the engine's cylinders are firing properly.
A P0300 diagnostic code indicates a random or multiple misfire. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. A P0302 code, for example, would tell you cylinder number two is misfiring. Unfortunately, a P0300 doesn't tell you specifically which cylinder(s) is/are mis-firing, nor why.

Symptoms may include:

• the engine may be harder to start
• the engine may stumble / stumble, and/or hesitate
• other symptoms may also be present

A code P0300 may mean that one or more of the following has happened:

• Faulty spark plugs or wires
• Faulty coil (pack)
• Faulty oxygen sensor(s)
• Faulty fuel injector(s)
• Burned exhaust valve
• Faulty catalytic convertor(s)
• Stuck/blocked EGR valve / passages
• Faulty camshaft position sensor
• Defective computer

Possible Solutions If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. 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 (a.k.a. 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.

Please rate