Question about Cars & Trucks
2001, Plug wire or spark plug. Time to replace all of them. Do a complete tune up..
Posted on Apr 22, 2015
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
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.
For example, a P0302 code means that the the car's computer has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #2; same condition in P0301 - cyl #1, P0303 - cyl #3 and P0304 - cyl #4.
A code P0300 (or 301, 302, 303 or 304) 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 converter(s)
Stuck/blocked EGR valve / passages
Faulty camshaft position sensor
About your 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.
So, your code P0170 is one that surfaces with certain makes of automobiles more than others. In writing this article I've added Mercedes-Benz-specific info since it seems that M-B (and VW) are most prone to having this P0170 surface along with misfire codes or other fuel trim codes. P0170 means there was a malfunction in the computer's control of the air:fuel ratio.
It also indicates that the fuel trims reached their limit of adding fuel while trying to compensate for a actual or perceived rich condition. When the fuel trims reach their rich correction limit, the PCM (Powertrain Control Module) sets a P0170, indicating a problem or malfunction in the fuel trims. It may also have a P0173 referring to the same malfunction but on bank two.
Potential causes include a vacuum leak, unmetered air leaks Fuel saturated engine oil Leak in turbo air charge hoses (if equipped) Possibly bad O2 sensor (If Mercedes, may require adaptation with M-Benz compatible scan tool.) Oil contamination in MAF connector or O2 sensor connectors. Also check ignition coils, cam and crank sensors, and oil sensor for leakage contributing to oil intrusion in wiring harness. Defective MAF (Mass Air Flow) sensor (especially on Mercedez-Benz and other European autos. There are a lot of problems with aftermarket MAF sensors).
If you have this code and access to a scan tool, observe the MAF sensor reading in grams/sec. The reading will be different for different automobiles, so get a good spec. I'm going to stick with what would be normal for a Mercedes (1.8L), since they have the bulk of the trouble. Expect to see at idle 3.5-5 g/s (ideally). At 2500 RPMs with no load it should be between 9 and 12 g/s. On road test, at WOT (wide open throttle) it should be 90 g/s or well above. If it's not in specs, replace it. Be careful of Ebay MAFs. Often they don't work according to OE specifications. If the MAF checks out and there is no oil intrusion at the connector, check fuel pressure and ensure that there are no leaks at the regulator internally or externally. Check all vacuum hoses and confirm none are cracked, disconnected or missing. Make sure there are no vacuum leaks at the intake manifold gaskets or tears in the air supply hose. If the engine is turbo charged, be sure the hoses are in good condition and have no leaks. Leaking turbo pressure hoses could cause a rich condition. Inspect the condition of crankcase vent hose under intake manifold and operation of check valve in the hose. (In the "What are the causes?" section) If there doesn't appear to be any problems with the fuel pressure, MAF or vacuum hoses, then inspect the O2 sensor connectors for oil intrusion. A bad O2 sensor could cause a P0170, or P0173. Repair cause of oil leak and replace oil-fouled O2 sensor.
This is location diagram...
Bank 1 is always the side of the engine with cylinder #1.
Bank 2 is always the side of the engine with cylinder #2.
Bank 1 is the bank of cylinders on the firewall side.
Bank 2 is the bank of cylinders on the radiator side.
Sensor 1 is the O2 sensor before the cat.
Sensor 2 is the O2 sensor after the cat.
So the one you want is the sensor AFTER the cat on the FIREWALL side of the engine.
Hope this helps.
Posted on Jul 13, 2011
seems a bit impossible, it is highly unlikely for this to be happening and the vehicle still run. p0300 is random misfire. not sure if it has coil packs but if it does thats where i would start.. you can remove them and have them checked\ or you can do it yourself if your careful to not get a little shock. just pull th plug wire off at the coil listen for change in engine idle or hold it close to the post on the coil and watch for a spark to go across from the wire to the coil post where you removed the wire. avoid that auto-zone who told you all cylinders were misfiring.
Posted on Jan 16, 2011
all the codes you have are all related to the fuel trim, this problem needs to be looked at with a european capable scanner for futher tests sorry.
Posted on Dec 05, 2009
Testimonial: "Very helpful diagnosis"
Here is a diagram of the firing order for you 3800 engine. Cylinders 1 and 4 are misfiring because the operate under the same "Coil Pack" and the coil pack has unfortunately gone bad. O'Reilly sells them for between $30-50 depending on the amount of warranty coverage you want. To replace, simply unscrew the screws that hold the coil pack in place. WAIT before unplugging the plug wires. Place the old coil pack and new coil pack next to each other, unplug one plug wire, then plug it to that same port on the new coil pack. then do the same for the other plug wire. Then screw your new coil pack in place, and start you car. should run fine!
Posted on Dec 14, 2009
Tips for a great answer:
Dec 04, 2014 | 2001 Pontiac Aztek
Oct 02, 2010 | 2001 Chevrolet Silverado
Aug 14, 2010 | 2000 GMC Jimmy
Mar 15, 2010 | 2006 Dodge Caravan
Jan 03, 2010 | 2001 Pontiac Grand Am SE
Aug 17, 2009 | 2001 Ford Econoline
66 people viewed this question
Usually answered in minutes!