My 1999 lexus es300 is still reading the codes P0300, P0302,P0303 after giving it a tune up.

SOURCE: 12 codes; 90174, p0171, p0175,p0300,p0301, p0302,

I would be very hesitant about just going in and replacing parts/sensors, especially those diagnosed from Electronic Control Module (ECM) Diagnostic Trouble codes (DTC's) alone, as quite often when multiple codes are present, they are often related to a songle malfunction/failure (Such as coil codes, and O2, rich/lean codes, etc...) - A p0171 and 0174 code is not indicative of a faulty MAF sensor - it is a code set when a lean condition is detected within the vehicle's exhaust...often caused by vacuum leaks, EGR valve malfunctions, BAC/IAC ( Bypass/Idle air control) valve malfunction, DPFE sensor malfunction, or the MAF "hot wire" is dirty, and can be cleaned with the correct cleaner, but instead of replacing a $250 MAF sensor; only to later find out that if you had the vehicle repaired by a trained technician, a $3 vacuum hose and a $50 ignition coil had initiated the multiple DTC's - So, sometimes it does pay to use a trained technician; especially with so many codes present - Like I said - If I were going to do the work myself, I would erase all the codes (Disconnect battery cable for about 10 mins - this will also erase the block/learn ECM settings and it may search for idle for a bit, but will straighten out with time - reconnect battery and start the car - then after the light re-illuminates, re-pull the codes, and most importantly test the sensors/parts indicated by the DTC's before replacing anything - that is if you want to fix it the most cost effective way possible, but, if you have plenty of money to waste you could always just go replace whatever the DTC's tell you is out of specifications, regardless of the cause...this might fix it, but may not as well - if you got lots of money and feel lucky it's the way to go - if not, test those parts and sensor before replacing them - there is a process for testing each of them....Thanks

Testimonial: "Thanks you so very much. The car was shaking and making a knocking sound and running very poorly and now the engine is locked I had in towed home."

Anura uk

• 229 Answers
• Posted on Oct 16, 2010

SOURCE: 2003 mercedes Benz C240 codes P0300, P0301, P0302

P0300 Random Misfire Detected
P0301 Cylinder 1 Misfire Detected
P0302 Cylinder 2 Misfire Detected
P0303 Cylinder 3 Misfire Detected
according to this fault codes first mark ignition coils
3 ---------------- 6
2 ---------------- 5
1 ---------------- 4
RB-------------LB
this right banks and left bank, please remove Ignition coils with lids and spark plugs from right bank and swap with left bank, if fault code change as
P 0304 Cylinder 4 Misfire Detected
P 0305 Cylinder 5 Misfire Detected
P 0306 Cylinder 6 Misfire Detected
You can Identify it's a faulty ignition system then next swap ignition lids from ignition coils be careful each coils have two lids one short and other long bit deference and when you remove and fix it to the car keep in mind correct order because each coil two different fire for two spark plugs don't mix up, if you mix it can create the fault code.if you detect any fault ignition coils or spark plugs or lids replace that and also whether god or bad recommend to replace spark plugs, find the right that's most important thing, if this way couldn't found the any ignition fault next step is check fuel presser, when the engine running fuel presser must be around 4.5 bar without engine running must be 4 to 6 bar if the fuel presser too low need to check two different things one is fuel pump other is fuel injectors, in this case you can swap injectors from right bank to left bank and find is the injectors leaking, if not leaking faulty fuel pump.is this information helped you? if yes please leave a comment,

SOURCE: P0302,P0303,P0304;P0300 and P1399 found by the

From www.hondasuv.com:

The P1399 random misfire along with one or more of these codes: P0301, P0302, P0303, P0304 -- indicates a problem with the valves. The B20 engines in the 1997-2001 CR-Vs are known to have problems with valves tightening and then 'burning'.

So the first question is when was the last time you adjusted the valves? If you don't know or never have, then have them adjusted. Soon...

Clifford Beard

• 1975 Answers
• Posted on Oct 24, 2011

SOURCE: getting codes P0341, p0300, p0301, p0302, p0303

P0300 is multiple misfire. The corrective action for this code would be to test your fuel pressure and the injectors. P0301, P0302, P0303 is saying in certain cylinders there is a misfire. There are two different engines so I wasn't sure which one you have and couldn't give you the correct testing procedures for the coils. P0341 is saying the camshaft position sensor readings are bad. Again I am unable to give you the correct tests to check this due to not knowing your engine size. Feel free to email me at [email protected] with detailed information about your vehicle and I will be happy to email you the testing procedures to narrow down the problem and help you solve it.

David Burbee

• 1871 Answers
• Posted on Oct 24, 2011

SOURCE: getting codes P0341, p0300, p0301, p0302, p0303 on

Hello! The Trouble codes are pointing at ONLY cylinders 1-2-and 3 (P0301, P0302, and P0303)...P0300 is telling you Random Misfires...P0341 is pointing at the Camshaft Positioning Sensor A (Bank One)...When you face the front of the engine, the Left Bank are cylinders 1, 2, and 3...Although TSB's are written for this problem that isn't much help since you'll pay for it anyway...

The solution is to replace the Camshaft Positioning Sensor A...Of course, check its connector first for bent, dirty or broken pins...Buy a can of Electronic Contact Spray and clean both male and female ends of the connector before buting a new sensor....Follow procedure below...Push two safety pins into the rear of the connector on the specified pin #'s...See diagrams below....Saailer


STANDARD MOTOR PRODUCTS Part # PC345.....Cost $80

1. Connect a Digital Volt Meter to measure voltage across the CMP connector terminals 1 (B+) and 3 (Ground).
2. Switch ignition to "ON", but Do NOT start engine.
3. Measure voltage between terminals 1 and 3 . There should be a minimum 9.0 volts.
4. Switch the ignition "OFF".
5. If reading is not 9.0 volts replace the sensor...
6. You'll have to remove the timing chain to replace it...

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