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i-CTDI blocked catalytic converter?

M

mutley

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Location
Wiltshire
Car
2005 Accord i-CTDi
I have a long-running saga with my 2005 Accord iCTDI tourer.

It is currently massively down on power and smokes hugely under acceleration (put your foot down and you can't see following traffic, even under moderate acceleration it leaves a black stripe on the road).

Independent garages were uncertain as to the cause, and I was reluctant to swap the turbo without getting it checked out, so I took it to a Honda dealer. They think that there is a blockage in the exhaust system and have recommended replacing both catalytic converters. Prior to spending the money on the catalysts (they seem to be available on eBay for sensible money) my local garage is proposing to knock the matrix out of them to confirm that it fixes the problem - it is booked in next week.

Has anyone else seen this "blocked catalyst" problem before? I would be interested to hear if anyone has any experience of this. The car has done 160k miles.
 
It's possible it's a blocked Cat Steve but rather than knock it out, get your garage to spray some DPF cleaner or Cat Cleaner acid inside it and jet wash it thoroughly with high pressure water. If they knock the matrix out, it will really smell and fail it's emissions test.
 
Before you do any of that check your air filter and the hoses that lead to your turbo. sounds like you are not getting enough air.
 
Has the intercooler and pipework been checked for leaks? Monitoring the MAP readings with an OBD2 reader should see this (or at least a boost problem).

Taking out the cats could well cause regular over-boosting, which will then cause the engine to go into 'limp' mode each time.
 
The usual test for a blocked exhaust is to measure back pressure at the engine end of things, though if your pumping out black smoke I would bet on something else eg Turbo not putting enough air into engine to match mapped fuelling.
 
Thanks for the comments guys. Knocking out the catalysts was intended as a precursor to replacing them (ie make sure that the cats are the cause before spending the money on replacements.

If I understood the guy at the Honda garage correctly he said that the real-time diagnostics were showing that the MAP was way above the ECU's MAP target so not indicative of an inlet fault. All of the hoses etc have been checked and I tried dropping out the air filter to make sure that it wasn't the cause.

It is going in to the garage on Tuesday, I will let you know how it goes.
 
ebod said:
From my experience of this.....get your injectors checked out.
Click to expand...

Hi Ebod

Thanks for that. Do they need to be checked out by a Bosch injection place or can they be done elsewhere?

My local garage has suggested that it is unlikely to be the injectors as the engine starts first time and is very smooth, and Honda didn't suggest this as the first port of call.

It's quite a trek to my nearest Bosch place so it would be very handy if I didn't need to go there .........
 
It's not your injectors mate, I've checked them already.
 
Tomas had the same problem and resolved it...speak/pm tomas..he fixed the issue with the help of wing
 
Latest news is that it isn't the catalyst - that has been removed and there is no improvement.

The injectors are coming out now and being sent away for testing and possible refurb (££££) and until they come back (maybe not until next week) I am in the garage's delightful loaner.

There are only two good things I can say about the loaner - the first is that it is free. The second is that when my daughter said "What on earth is this thing?" when she got in to it, I was able to say "this is the car you will be driving when you are older if you don't work hard at school"!
 
Steve - can I ask why you think it's the injectors and not the turbo?
 
Hi Fahad

I don't have a view on what it is - I have given up trying to second-guess.

Honda didn't think it was the turbo, the local garage don't think it is the turbo, Honda suggested injectors as the next port of call if it wasn't the cat. If i recall my conversation with him correctly, the Honda guy told me that the actual MAP was ahead of the target MAP.

I did quiz the Honda guy about the injectors - as he would have been able to see the calibration on the HDS. He seemed to think that there is the possibility of problems with the injectors which HDS can't see. I have no idea about the veracity of that statement.

To be honest I have got to the stage where nothing would surprise me.

Injector test / refurb is what the local guys have suggested next.
 
Hmm I suppose anything is possible. Keep us posted, let's see..
 
Hello,Steve,just try disconect frequency solenoid valve and if you have power again,it's your frequency solenoid valve gone.So my car still smoking,couple weeks ago I fixed injector seal.But still smokes.All my intercooler was covered of oil,I changed too.But car still smokes.I have another EGR valve.After cleaning bouth parts,if I put one,car not smoking,but from 1000-1500 no power.If I put another egr,car have power,but smoking,not like was before but still.I spoke with Honda dealer,they said,that all egr valves not good second hand.So better buy new wich cost 599£.So if you disconnecting frequency solenoid valve,before must disconect batery.I am going for injector test monday.Let us know.

Good luck.
 
Tomas I know someone selling a nearly new EGR valve for your car. I'll drop you a line with his number.
 
Tomas44 said:
Hello,Steve,just try disconect frequency solenoid valve and if you have power again,it's your frequency solenoid valve gone.So my car still smoking,couple weeks ago I fixed injector seal.But still smokes.All my intercooler was covered of oil,I changed too.But car still smokes.I have another EGR valve.After cleaning bouth parts,if I put one,car not smoking,but from 1000-1500 no power.If I put another egr,car have power,but smoking,not like was before but still.I spoke with Honda dealer,they said,that all egr valves not good second hand.So better buy new wich cost 599£.So if you disconnecting frequency solenoid valve,before must disconect batery.I am going for injector test monday.Let us know.

Good luck.
Click to expand...

Hi Tomas

Thanks for the input. The frequency solenoid valve has been replaced, the EGR has been cleaned and tested OK and the car has Fahad's "EGR Off" remap so it probably isn't any of those things.

I'm still not convinced that it isn't the turbo, but the people who one pays to know about these things say that it isn't. I am not looking forward to the bill for the injectors, and I really don't believe that they will solve the problem.
 
It's possible it is the injectors, but when I tested them, although not perfect, they were all well within tolerance.. and really your problems seem related to boost not fuelling. Let's see what happens anyway..
 
Well it seems like it probably isn't the injectors - they have been checked and although one has an incipient fault (which will, of course, cost £££ to fix) it isn't something which would have caused the symptoms on my car.

Injectors should come back in the next day or two then we are off again on a guessing game. The garage is going to gather some live data before we decide what to do next.
 
mutley said:
Hi Tomas

Thanks for the input. The frequency solenoid valve has been replaced, the EGR has been cleaned and tested OK and the car has Fahad's "EGR Off" remap so it probably isn't any of those things.

I'm still not convinced that it isn't the turbo, but the people who one pays to know about these things say that it isn't. I am not looking forward to the bill for the injectors, and I really don't believe that they will solve the problem.
Click to expand...

Hi,
Personally I think,that yours EGR not working.I cleaned one And another clened my mate.So no different till yestarday afternoon.I bought nearly new EGR ( Thanks for Faddy's help) and looks,that car smokes much less.
 
Anyway let us know.I wish that you can sorted problem.
 
I still think it's your turbo (sorry I know I keep saying this).
 
I have got to the stage where nothing would surprise me!

I will let you know what happens next. Called the garage today but the main man was off sick ..... so I may be in their loaner for a few more days yet.
 
Injectors won't be back until Monday, so I have another weekend in the garage's "dream machine" loan car (a "T"-reg Renault Clio .....)

When Honda looked at the car they seemed to think that it was over-boosting (actual MAP exceeded the required MAP), yet the car is producing black smoke which is indicative of unburnt fuel (too much fuel or not enough air).

That got me wondering whether a faulty MAP sensor might be to blame - anyone know what the typical fault modes of the MAP sensor are, and what the symptoms are?

Thanks

Steve
 
Well, the car is fixed now. Short answer is that it was the EGR valve.

Long answer:

Garage had inspected the catalytic converters as diagnosed by Honda - that wasn't the problem.
Injectors went away for a refurb - one was below spec, but OK. Refurbed and installed - no problem.
Garage blanked off the EGR valve - car is now fine but if left on tickover or over-run the engine light comes on and it goes in to limp-home mode.

This puzzled me as the car has had Fahad's EGR-off map on it and the EGR has always chedked out fine on HDS. Spoke to Fahad, turns out the "EGR-off" map actually opens the EGR a bit on tickover and overrun to help meet emissions reqs and to avoid other fault codes showing, so it still needs the EGR to work a bit. No idea why it passes the HDS tests and then causes a problem, but life can be strange that way.

Replacement EGR bought for £30 off eBay. Fitted - problem now cured. Car goes like a train. Still a bit of smoke and a soot trail if you floor it in 1st gear, but nothing anywhere else.
 
Glad it's fixed mate, it was a real puzzler this one, but I have seen it a couple of times now which is why I always say we need a working EGR before we can switch off. Normally however we can identify before mapping if the valve is working or not, and yours passed the test on both occasions. I can only think it was slow operating and on its way out..

My guess is that yours wasn't fully closing, rather than not opening. If you still have the old one, can you take it apart when you have time and inspect the seat and springs to see if it was closing fully.. maybe share the pics.

I know member Jayok recently took his apart and had the internals exposed to check for spring movement.
 
Hi Fahad

Thanks for all your help - this one had everyone scratching their heads. Honda would have had me spending £1,200 +VAT and fitting for catalysts, plus £££ for injector refurbs / replacement (I think they charge about £400 each) ..... and still no guarantee they would have identified the EGR as the culprit, so I think I have got off fairly lightly!

I've got the old EGR so may try stripping it when I have some time to spare.

The car is fantastic now, hard to believe that it has 160k on the clock.

Steve
 
At least you are now feeling the full potential of the car and the remap.
 
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