So yesterday as I was driving to work, I got a flashing Check Engine light. I took out my obd reader and checked what codes i got. I got a P0307, Cylinder misfire in cylinder 7. I went to autozone and bought a new spark plug hoping thats all it was, but it turned out not to be. I bought a replacement ignition coil from autozone since i needed to get the car operational asap. I installed the new ignition coil and voila, the problem was fixed! I then went to replace the coil cover and had trouble, so i removed the mushroom looking pcv valve to have more space and ended up breaking the plastic breather hose. (See item circled in red in picture) I took a plastic hose from my oil filler funnel and replaced the original hose with that one. Everything seemed fine until this morning when i gassed up to pass someone on the highway and got a Restricted Performance and a bunch of codes: P1316,P0351,P0354,P0356,P0357, P0300,P0301,P0304,P0306,P0307,AND 01367!!! So i took out the engine cover and turned the engine over and it seems that the hose is undergoing too much pressure and clogging itself. Could this hose be the issue causing all of this? Thanks so much guys!

[IMG]pcvhose by edavidadorno, on Flickr[/IMG]

 

UPDATE-So i bought a more rigid hose from a local parts store and everything seems to have disappeared now. No more faults, no more restricted performance! I wont know for sure if this repair is 100% until i drive it for a bit. Wish me luck!

 

Good luck!

Flashing MIL = catalytic damage being done. Hope you fixed the cause, in which case likely only minor damage.

 

Yes I did resolve the issue! For the future, never replace the plastic breather hose from the PCV with anything but a rigid hose!

 

I am guessing that the hose was collapsing under vacuum since the engine sucks air from the sump via the PCV.

This explains the clouds of smoke on kick down which I have experienced in the past and which BTW I tested recently with no smoke at all.

I am very surprised about the codes resulting from this fault ie how does the system 'know'?

Mass air pressure sensor goes -ve?

The other point is how does the PCV work?

There doesn't seem to be much in it, is it just a diaphram which shuts under vacuum?

Does all this explain why the pipework is corrugated ie to resist collapsing under vacuum

Cheaper than fitting smooth wall pressure/vaccuum tubing.

There is a lot to learn about this Jag!

 

Can you tell me where you got the replacement hose or brand name? I just noticed that exact same hose was cracked on mine. I have duct tape holding it together for now!

 

In answer to your questions, yes the pipe i put in at first collapsed under the pressure of the vacuum causing all these codes to show up and restricted performance. In reference to the type of hose, i simply went to an autostore and got a rigid rubber hose cut to length that fit tightly over the original fittings.

 

Thanks for the reply. That hose is pretty hard to source, but I finally found a new one for $60.00. Waiting for it to arrive, then I'll pop it in.

 

Yea i saw them going for that price on ebay. Couldnt justify paying that, and i couldnt see myself putting a hose back in that will become brittle down the line again. The hard rubber hose i put has been working flawlessly since! And only $2.60!

 

So all this fanfare for nothing unfortunately. Due to my negligence, the car began throwing all these codes like i mentioned in the beginning of this thread. Turns out the rubber hose i put in place of the plastic breather hose began to soften and eventually began collapsing on itself. So i purchased the same hose again from the same hardware store and the codes and restricted performance went away. I drove for a bit and no issues until i throttled up to switch lanes and got the dreaded "Restricted Performance" message and a bunch of codes. Needless to say, i ordered the official breather hose and am hoping that upon receipt, all these problems go awaY! I will keep you guys posted but for future reference, the rubber hose is only good temporarily!

 

So i replaced the hose today with the official one and the car started right up and no issues whatsoever. As it got warm all of a sudden it threw the same error as before. Restricted performance and a blinking check engine light. Anyone have any idea what could've happened here? Clearly it's something to do with the hose. Thanks again guys!

 

Flashing MIL normally means misfires so bad they're causing cat damage there and then.

Bad coils?

 

I agree it would seem like bad coils but the engine runs 100% before it gets to operating temperature. the coils were working before, but i do get misfire codes and ignition coil failure codes but the last time that happened it was all because of that breather hose. now i changed the hose and im still getting the same problems.

 

Bad battery's another option.

Gonna need new cats if you don't fix it

 

I hope i havent done damage to the cats as thats an expensive undertaking. i will try a new battery i guess but this didnt start happening till the hose broke and now that it has been replaced, it doesnt become an issue till the car is warm at normal operating temperature.

 

At least try that / swapping coils to see if fault moves or there's something in plug wells.

 

I will check it out, thanks JagV8! Another question, say something got sucked into the pcv valve or the other end that goes into the throttle body, could that be causing an issue? Or could the pcv valve become defective after it gets warm?