Apologies, this is a long un'...

I don't drive my car that often, it's a MY00 which has been entirely faultless for 6 years but about 6 months ago it got the multiple misfire codes across all cylinders and indeed the random misfire code of P1399.

When did it happen?

The CEL first came on after 2 things;

1 - I over oiled my K&N filter a bit
2 - I used Supermarket Super Unleaded for the first time ever, previously the rest of the time it's V-Power

Symptoms

1 - CEL which only ever comes on at IDLE not whilst moving (significant?)
2 - Uneven idle, between 600-900rpm
3 - Puffing exhaust
4 - Not as smooth when lifting off accelerator in gear

Because I thought it was down to the filter oil/bad fuel, I went about trying the following to resolve;

Steps Taken to date

1 - Used Fuel Cleaner/Injector Cleaner in fuel
2 - Removed and cleaned all air filter elements, re-oiled, ensured it was bone dry
3 - Sprayed Carb cleaner down throttle body and cleaned out
4 - Did Map Whack and fastened on with cable tie
5 - Did Valve adjustment and checked plugs
6 - Removed and cleaned IAC

What Next?

After I did the above, perhaps unhelpfully all around the same time, it was absolutely fine for about 3 months (approx 800/900 miles)and then it came back again, seeing as the car was driving perfectly well I reset it and it was fine again for about 600 miles then it came back on again - this time just with P303 and P1399 instead of across all of them. I'm now in the process of reading through the thousands of posts made on the subject but it's hard to isolate the issue as I can have a list of 12 things to check and do one thing then reset and it will be fine for weeks/months which will take ages to find out what it is?!

Because the codes are multiple and not that often, I'm leaning towards there being a problem with one of the sensors, i.e. it was maybe fouled by the oiling of the air filter, so I'm trying to tie down exactly what each sensor should be doing against what it's actually doing. To this end I bought a bluetooth OBD adaptor and the Torque app on Android which measures a load of values, most of which I have very little understanding of - which is where I need the help of you lovely lads and lasses.

If you guys tell me what values I need to measure and when, i.e. at cold, 2 bars, 3 bars etc then I can post the values up for someone who knows more about it than I. There are dozens of potential things it could be, so it's utilising the collective expertise on here that will hopefully point me in the right direction, at the moment based on what I've read, cleaning the injectors sounds like the next logical step - one value I did read about and check was the fuel trim which looked to be negative in single figures, unsure of how telling or not this might be.

Also, if anyone is local to Leeds and fancies a closer look with any equipment or to swap parts over to rule things out you are more than welcome, you'll be rewarded with alcohol, food and a warm sense of wellbeing...

If you got this far, well done, do you have any thoughts?

 

Good post.

Have you read my post in the FAQ?

It could be that the oil you used has been sucked in my the MAP sensor and screwed it up. Whacking it won't help you there. You would need to read the map voltage signal, or just buy a new one as really they should be a service item.

Second thing i'd suggest is injectors and / or coil packs.

Getting you injectors cleaned and tested is pretty easy once removed, and there are companies who can turn them round next day. Or get a second hand set.

Coil packs also are a popular failure.

I'd ingore whihc cylinder the misfire is detected on though, it's not an exact science how the ECU calculates this.

 

a refreshing post that doesn't just state 'tell me what to do from start to finish'

MB's thread is a corker and has helped many out thus far...well worth a read

 

Cheers both, I guess there is no point giving half a story if I want good specific advice!

I'd not seen your thread before Mark, which is surprising given I've been searching high and low for info on this!

Just a couple of queries;

1- On the MAP, is it likely to have been badly fouled when there wasn't much evidence in the pipe leading off the filter when I got my hand in to check for oil vapour (or would it have evaporated/been sucked right through via the MAP?) I guess I did do this months afterwards...

2 - Based on the excellent sensor description and when the o2 sensor is used (at idle and light throttle) these are the times when I have issues, so this could also be the culprit?

I'll price up a new MAP and also see if the OBD tool has o2 voltage on, I think it does actually so will check if it's putting out the numbers you suggested in your post/if it's sluggish - if it was failing though, wouldn't it put more fuel in which would give a positive, not negative fuel trim? I'm learning slowly but surely ;D

Will report back!

 

if we think it's the K&N oil thats caused it, wouldnt it be worth removing all the sensors along the intake system and giving them a clean out with carb cleaner, along with their pipework? (eg a spray down the MAP sensor hole in the intake body once you remove it)

while your at it, it might be worth a clean out of the IACV, as per FAQ this can cause poor idling - again, carb cleaner

 

I did all that, used electrical cleaner on the plug too and it's still the same...

 

I don't think any of the other sensors, other than the MAP, will potentially cause a misfire. You can spray stuff in the MAP, but I try and avoid it. Plus if it's gunked up it's not likely to be recoverable imo. Worth a shot I guess.


Jim, it's rare you get such a well explained fault, and I do now tend to ignore some of the shit "help me" posts where people don't give you any info

The o2 sensor shouldn't be the culprit - it if fails, it fails on the rich side and wouldn't cause a misfire. Again, I treat these as service items. Eample being, I just changed mine on the Clio and gained about 5 mpg (or so the GF tells me!)

RE the MAP, it does suffer from oil mist ingress from the engine crankcase breather so that can cause it over time, plus the oil from your filter. Preferentially it will get sucked in and munched by the engine vaccum but stuff can still get in.

I'd suspect it's an injector or coil (or valve clearances but you have checked them) but MAP is an easy one to rule out too. Maybe swap with someone else?

 

Cheers Mark, your help is appreciated!

I'll look to get another MAP I reckon, the car is 11 years old now so even if it's not that I'm sure it would appreciate it!

Anyone know of a good place to get one? I've used HTG before and his delivery costs were much cheaper ($65!), so might be as well ordering over here unless he will send one cheaper...

Alternatively, if someone has one lying around that I could borrow for a day?

 

I have a couple of used spares in the garage but won't be able to post it for a couple of weeks

If it's 11 years old and not had an 02 sensor, i'd do that too if it were mine. Depends if you know the history of the car I guess, and you can always check the voltage response from it.

New MAP and lambda will make it drive like new

 

History wise Mikey had it before me!

If you would post me one over to try that would be great? I'm down south next week and anything ordered the week after would be caught up with the holidays etc anyway so that might be a good option... Hopefully it won't die on the way/way back...

I'll look into o2 sensor too, any ideas on where is best to get it from and what a reasonable price is ? is it the primary one?

Someone else on here bought a generic 4 wire one (for 20 odd quid) which he says works but it involves crimping and cutting wires though to be honest my trusted indy would be doing it...