Can some one help me in this,
I have a 97 Jag xj6L with a
Check Engine Light On with codes
P0300, P1313, and P1314.

As i understand codes P1313 P1314 is the
Definition of Misfire Rate Catalyst Damage
Bank 1 and/or 2

But im having a problem finding the definition
For code P0300
Can some one please help me with this code
Or what do all these codes mean together??
Thank you

 

P0300 is random misfire usually accompanied by another more informative P03xx code indicating which cylinder(s).



The right hand column shows the possible causes.

Graham

 

Change.spark.plug and.coils

 

Yep do that, but also replace all the fuel injectors and the harness to them. Also the fuel pump, the fuel filter, the fuel pressure regulator and may be even all the fuel pipes while your at it.

Don't forget to pull the cylinder head and change the gasket and make sure you replace all the valves while it's off just in case one is burned out.

For good measure replace the MAF sensor and the Crank sensor.

If all of that fails, you would then need to do some diagnostics to see what the actual problem is.

 

So basically spend all sorts of time and money on replacing things that might not need it these cars sell for 2500$ us so I doubt doing all of what you said is economically smart is there not a scanner tool for jags that can help trouble shoot also the manufacturer says p300 is one of six things fuel contamination or injection issues fuel pressure and the some sensor issues that would throw additional codes I have the p300 1314 this car is so difficult to figure I have replaced everything from fuel filter battery alternator oil and filter transsexuals fluid and filter air filter coils plugs cam cover gasket egr value tps sensor even replacement front cats exhaust manifold and you pipe rear right muffler and fixes all the interior and still less then 14 mpg also can of sea foam in tank and sea foam in the vacuum line to clean out carbon someone help it's crazy also can someone tell me what the pop sound when engage to or from reverse?

 

Sorry bout that

 

Whoa, ease up Tex

b1mpc is just teasing VDP408. Given the age and milage that the X300s are at, the most common issue causing a misfire appears to be coil failure. That's why VDP408 advised to swap your coils and plugs.

All b1mpc is suggesting is that we come up with a better diagnostic approach before your shell out $400 bucks for new plugs and coils.

We're all friendly here.

-HC

 

I love it. Right on.

 

AND... I'm betting that would not fix it since it is random misfires!
Back to the diagnosis. In addition to the chart, I would look at the fule trims to see if I could ID a fuel problem. I might suspect the CKPS. What drivability issues is the car experiencing.

Now, about the procedure to filter transsexuals fluid...

 

Is there a way to reset the trim or is there a diagnosis tool for under like 200 that can show me the fuel trim and o2 response I have replaced the coils with bosch and the plugs with oem and oh and yea I'm super frustrated with this car and especially mechanics in my area.. I have had four import guys tell me nothing other than its missing on all cylinders and the P code tell me that.. I have a suspicion that it is the ecu or o2 sensors maybe MAF but I was told a computer will not cause a miss... Only Rough running mine is throwing codes. also someone here mentioned o2 reorientation with the jag pdu I can't find a pdu not even listed at all any information is so appreciated

 

So im the original person who started this thread. I had codes p0300,p1313 and p1314. I found out that code p0300 stands for Random misfire. And P1313, p1314 are misfire bank 1 and 2.
I replaced new coils, new spark plugs, new MAF sensor, new head gasket. Nothing seemed to get rid of those codes. Untill i finally replaced all four O2 sensors. The two on top on two on the bottom. That solved the problem in My car, check engine light was gone my cat is back on the road.

 

Original poster thanks I'm gonna replace mine ASAP what brand or can you post a link for the items the prices I'm seeing are widely varying I'm glad all these people can help and this also confirmed a bad sensor will cause a miss and that the P 300 is also a code for failed lambda...witch some have suggested. Sorry for jumping on your thread I've been having this code for 7 months and I'm Out of options. I'm not a forums type guy more of a lurker..but this community is great very helpful.

 

I bought my O2 sensors at rockauto.com the brand that i went with was Bosch. Two upper and two lower. When you disconnect the O2 sensors make sure to connect the new ones in the right place check that the colors in the wires are the same.

 

And don't worry about jumping on my thread. Im not a mechanic but my car was driving me crazy and I had tried everything I could. This forum was a great place for advice and suggestions. I hope what I found out with mine helps you a bit with yours. Good luck and let us know how it turns out.

 

Greeting from Baja!!
I just joined this forum today, I bought this cat several years ago but have not put enough miles on it. It's registration time, and as you all know it's got to be smoged. I plugged my scanner to it and it showed DTC's P0300, P0303, P1313 & P1314 looking for information regarding this codes is how I came across this great forum, my questions were answered without having to ask, thanks guys God Bless!!!

 

Welcome to the forum, Mike! Make sure you stop over at the new members section and make a short introductory post. It will allow other members to extend a proper welcome to you and also alert the moderators to your presence so they can upgrade you to member status once you hit the prerequisite gates.


Glad you got it sorted,

 

Thanks to all on this thread. All great stuff.

The observations that I have are that an oil leak can cause a plug to misbehave, particularly when hot. My plugs are only 1500 miles old but there's visible oil in the spark plug well. New gaskets required - we'll see whether the plugs can be rescued. I've invested in a code reader that also indicated which plug/coil cylinder was to blame.

Also, an auto transmission that doesn't change up in good time can (apparently) produce a misfire code (ie the engine is labouring somewhat).

Worry about the state of the Catalytic converters can be overstated. These engines should be close to passing emission standards (in the UK at least) without 100% serviceable converters. I've used genuine second-hand O2 sensors and have been lucky so far.

Cheers,

Malcolm

 

Reviving this old thread. Occasionally had a P0300 code but I also had O2 sensor codes. I replaced all 4 and a couple of miles down the road I got the flashing CEL and then it came in solid. Checked the codes and P0300 and P1313. I cleared them and they came back again after a few miles. But here's the thing, the car is running better since the sensors were replaced, definitely more responsive. The only issues are at low RPM it has a little bit of slow acceleration and fuel consumption is probably a little lower than it should be. This was true before the O2 sensors were changed and maybe a little better since. I replaced the fuel filter recently and the plugs and coils have less than 10K miles. I also installed Andy's bracket.

When the code flashes there is no change in engine performance whatsoever.
Are there any modern OBD2 readers that might be more useful than the basic one I have or is the computer in these too old to give more useful info? Thanks