P2458 DPF Regeneration Duration DTC

[bigshorty]

Hi All

Wondering if anyone can help with a idling issue I've been having with my 2006 Ford Focus 1.6 TDCI.

The other day, on a 25 mile journey, I had to pull up at a set of traffic lights. When I did the car started idling erratically between 500 - 1500 rpm, as I pulled away from the traffic lights I noticed the car jerking and/or hesitating slightly. After no more than 5 minutes more travelling after this started the car seemed fine again. A few days later on another journey, I heard the car idle a bit oddly again, but no where near as bad as the first time. I did a Forscan on the car and the DTC code P2458 showed up, however no engine management light was illuminated. I did have the red EML with an exclamation mark in a cog show up on the dash about a month ago, so I took it to my mechanic mate and we found out that the Eolys additive tank was empty. We filled the tank back up, reset the counter and cleared the DTC and all has seemed fine since, until now. As I said the Forscan I did recently showed the P2458 again, however it hasn't lit the engine management light up this time. Does anyone know what could be causing P2458 to pop up again, and could this be related to the slight idling / running issues I've been getting recently. The majority of the time the car seems fine, running as it should, although I don't seem to have noticed the usual signs of the car doing a DPF regen lately, although how obvious it is to notice a regen is unclear to me.

Any ideas on what could be causing the problem with idling and DTC P2458 would be greatly appreciated.

[TomsFocus]

That rough idle and jerking was probably the start of a regen.

I used to get that code all the time, fitted a new dpf which lasted 3 months before the code started coming back again.  

How many miles has your car done?  Original DPF?

 

[bigshorty]

Cheers for the reply.

Car has done 110k. I was told when I bought it that the DPF had been changed at just before 100K, no paperwork to support that though due to mechanic mates rates, but then again he did tell me that the Eolys additive was topped up, yet it ran out a couple hundred miles ago. I read that a faulty exhaust gas temperature sensor could cause imcomplete regens, DPF over fuelling and throw up DTCs that don't necessarily light up the EML. Not sure if this could cause rough idle / jerking??

[bigshorty]

Just to add to this discussion, I think I've worked a possible cause as to why DTC P2458 has popped up again and why I think DPF regens aren't happening. To clarify I'm sure the first time P2458 popped up was down to Eolys fluid running out. 

Just over a month ago I blanked the EGR valve, as the pros of doing it seemed to far outweigh the cons of not. However, at around the same time I was noticing the EGR valve was playing up and throwing up fault codes, but as I was blanking it I thought I didn't need to worry about it. Since then the EGR valve is constantly giving the same fault codes, which I just monitor and reset every now and again. I've been doing some more research on the P2458 DTC and I have read on someone's DPF woes that for a DPF regeneration to happen, all sensors, valves, etc that are involved in the regeneration process need to be working properly, if fault codes are popping up then the regen will not complete. I'm now wondering if the fault codes coming from the EGR valve are messing about with the regeneration process. Could this be a possibility anyone?

18 hours ago, TomsFocus said:

I used to get that code all the time, fitted a new dpf which lasted 3 months before the code started coming back again.

TomsFocus

I read through your discussion regarding DTC P2458 that kept popping up, did you manage to get to the bottom of why your car was doing this?

[TomsFocus]

32 minutes ago, bigshorty said:

TomsFocus

I read through your discussion regarding DTC P2458 that kept popping up, did you manage to get to the bottom of why your car was doing this?

Yep.  Basically DPF's are *a word I can't say on here* lol.  There was nothing wrong with my car, no sensor faults etc, my driving style isn't ideal for them as although I drive hard, I don't tend to do more than about 20 mins of motorway at time but apart from that I honestly couldn't find any reason for the DPF constantly filling up and not regenerating properly.

Did you have the EGR mapped out when you blanked it?  They can't just be blanked on the 1.6, that'll be giving some weird driving characteristics as the ECU will be expecting a certain amount of air though the EGR as well as the MAF under some situations which is how it works out how much fuel to inject, probably explains the hunting idle you had previously.  EGR is also used during an active regen, without it you probably wont get the DPF hot enough.  Personally I'd remove the EGR blank, force a DPF regen if possible and then see how it goes from there. 

[bigshorty]

Cheers for the info Tom.

With regard to your question about mapping out the EGR, no I haven't had this done, which sounds like it could be the cause of some of the issues I'm having.

I was getting to the point of wondering whether blanking the EGR was such a good idea after all, it did produce some good performance results, but have my concerns as to whether blanking it has caused these little glitches since. Like you, I don't really use the car a great deal and it certainly doesn't have much in the way of long motorway runs, all in all probably not the best choice of car for me, which is a shame as it does drive well.

I will remove the blanking plate and give it a regen soon and let you know what happens.

Cheers again for your comments.