so the car failed for high CM, ive changed the plugs and filter, ive checked the lambda reading using easy obd 2, it reads a steady 0.8v, if i rev it it goes to 0.9v then down 0.3v then up to 0.8v again, im assuming the lambda is ok as it does fluctuate, im at a loss as too what else it could be.

 

What car is it?

 

the wifes honda accord

 

Put the car in the garage with the engine running. Hopefully it'll kill itself and you can buy a new one

 

CO is unburnt fuel I think. Could be a knackered cat, poor ignition. I'd pull the plugs out of it and check to see if they are a light greyish / brown colour. If they are sooty then something isn't right. What year is the car? What sort of use does it get?

 

thanks for a sensible reply, car is used daily but never thrashed, its a 2001 generation 6, here are some pics of the plugs ive just replaced









there are no fault codes stored or pending, engine is also not down on power as i'd expect with a blocked cat.

 

Those plugs look perfect, just as they should be. If it were me I'd be looking into swapping out the cat, maybe it's not doing it's job properly. New ones aren't cheap though, maybe see if you can get a 2nd hand one.

 

yeah a new 1 is £870-odd, more than the car

 

Oxygen sensor is showing the same problem as the gas analyzer. Mixture is a bit too rich.
Front Oxygen sensor signal should be switching between low (0.1-0.2V) and high (0.7-0.8V).
Rear Oxygen sensor should be a steady 0.8 volt.
Make sure you look at the correct Oxygen sensor. You have 2 of those.
Check the pid called Fuel System. Is the car in "closed loop"?
Check the coolant temperature reading.
Catalytic convertor is unable to convert CO into CO2, because of the rich mixture there's no Oxygen left in the gasses. So, maybe when you correct the mixture problem, the cat will work again.

 

yes easyobd2 shows these as bank 1 sensor 1 and bank 1 sensor 2, both give very similar readings (0.8v) but not identical

not sure what you mean by pid but the car is in closed loop mode

80+degrees raising to 90 when the cooling fans kicked in

and there is my problem, how do i adjust the fuel when i dont know whats wrong.

 

Are there any fault codes (DTC's) present?

 

no fault code or codes pending.

 

Very, very strange.
You have an Oxygen sensor signal stuck at rich, a Lambda control which is doing nothing but still no DTC's.
I would recommend to read codes and live data with Honda dealer-equivalent equipment.

Ecu is standard? I.E. Not chipped/remapped?

 

car is totally standard, no mods of any kind.

 

There is something you may not have considered, as it is an 11-year old car the valve guides or the bores may be worn, the blow-by gasses contain carbon monoxide which are fed into the intake via the crankcase breather/s to be re-gurgitated by the engine, which can find its way to the exhaust (if its not burnt) or contaminate the cat

a catchtank or a re-route of the breather (vent the crankcase/ block the inlet) would be the cure fior this

the plugs look normal on the electrode/ tip insulation but are blackened around the rim, it could be running rich at certain conditions / revs and normal at others, there may be a faulty sensor or the ECU thinks the car is cold when it is warm, and running rich (like the modern equivelant of a choke)

i wonder if a grade hotter plugs would "fix" it enough (just for the MOT?)

 

do you have any way of simulating the sensors ? this whay you could make the car think it is running rich (test only at idle) and see if leans out the mix. Also where does the ecu get its engine temp signal from? test that sensor (normally resistive in the bench then in a cup of boiling water!

 

well there what i think is an air intake (can hear the air being sucked in) just below the air filter and to the left of the battery in this pic, i could cover that and see what happens?

pretty sure the thermostat is ok as both the dash and my laptop software are getting 80+degree temp when warmed up.

 

How long was the tester revving the engine at fast idle for. when I get figures like that I hold the revs up (2500-3000rpm) for a while and 90% of the time the CO level comes down .try to give it an 'Italian tune up'

 

dunno as i dropped it off.

 

i bet if you gave it a good thrashing up to the mot station and they tested it without turning the engine off that would go through, i see it all the time. sometimes just holding it at 2000 rpm just isnt enough to clear the system out or get the cat hot enough.

also there is nothing to say he revved it at all, it just says manual observation. a common trick is to let it go through on idle and if it fails try and sell you a service etc

 

so i blocked that "intake" i mentioned, it did bugger all to the lambda readings

took it for an "italian tune", did bugger all for the lambda readings

whilst driving i noticed:

under heavy/full load sensor 1 was 0.8 - 0.9v and sensor 2 was 0.025 - 0.035v

on overrun both sensors showed 0.00v

cruising along sensor 1 0.8v sensor 2 0.7 - 0.8v

on idle they show the same as cruising

 

if you block the engine air intake it will make the car run richer - (some cars have hot/ cold - summer/ winter air intakes) - better to fit a fresh air filter if you want to get it to run less rich/ leaner

i presume you have not tried blocking' venting the breather or running hotter plugs as i have suggested?

the actual engine temprature is one thing (controlled by the mechanical thermostat/s) the temprature the ECU "thinks" it is can be totally different (as measured by the electronic sensor/s)

somtimes you can get "bogged down" with sensor readings/ fault codes - the problem and solution can be deceptively simple - like a loose connection

 

Last year my old E39 BMW failed its MOT on the same thing. I put a new cat on it, dropped some Forte in the fuel and took it for a good run then back in for the re-test and it was perfect.

A brand new, non-genuine cat was £90 with a 25% club discount I had.

BMW parts are dirt cheap though if you stay away from main dealers as there's just so much choice. I bought an air suspension unit for the same car for £110 and it was a fully stamped genuine BMW part, but the main dealer wanted over £600 for the exact same part!

Jap cars aren't as easy to find these bargains for in my experience, but do some research, there are cat specialists out there and some cars can use a ceramic cat rather than a precious metals type and are therefore MUCH cheaper. They have a lower life expectancy, but should still last a good few years and you should be able to but at least 5 for same price as a genuine one from a dealer!

 

i have already change the plugs so see no reason why i need hotter ones as the emission have been fine for all previous mots

i dont know where the breather is so cant do anything about that, also believe that a blocked breather would cause black smoke (know of serveral ppl that have had this and thats a symptom)

the guage is showing how, the laptop software read 80+ and it running in closed loop.

 

reckon its the cat then?

i think the lambda's are ok as they alter in voltage just not at idle

from honda £872.46

from eurocarparts £271.80 or £85.63 both are React, i asked what the difference was, apparently 1 will last longer.

 

The React one is what I fitted to my old BMW, I fitted the cheaper one, which iirc was ceramic rather than metal lined. They only guaranteed it for two years iirc, but it ran perfectly with that fitted.

Buy from Euro Car Parts online and put the code PARTS25 in and get 25% off.

 

both the reacts are ceramic not sure about a gen honda.

i plan on looking at the cat tomorrow, am i right in thinking if its intact and i can see sunlight through the honeycomb its ok or can it look ok and still be goosed?

 

It can still look ok and not function properly.

Someone else may know more than me, but I know of no sure fire checks that a cat is ok without having it on the emissions machine.

 

£10 worth of fuel in it and a bottle of redex and give it a blast down the road. worked for me before with a wee corsa.

 

did that fail for the CM being too high?

 

was years ago but am pretty sure it was. put it into the dealer for an mot like a twat and it failed on emissions. was told to try that first. i remember it making a huge difference to the readings on that car.

 

here's a little clip i made, car was warm but not to full temp at the start, i gave the throttle a blip around the 6 minute mark.

all this was at idle

http://www.youtube.com/watch?v=EOBcx...ature=youtu.be

 

to update, fitted a new cat and it passed its mot, next day however the MIL came on and got the following codes

P1166 Primary HO2S (No. 1) Heater System Electrical
P1167 Primary HO2S (No. 1) Heater System
P0136 Oxygen O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2)
P0138 Oxygen O2 Sensor Circuit High Voltage (Bank 1, Sensor 2)

the MIL was not on before the new cat was fitted, i tried to richen the mixture by blocking the air intake, tried to weaken it by removing the air trunking, it all does nothing, voltage stays at 0.8v, checked the lambda is getting the heated and its getting 12v on the engine loom side.

at wits end now.

 

So the car has passed its MOT

Does it start and run?

 

is that a trick question? yes it starts and runs, if it didn't I'd be asking why doesn't it start or run, it runs as it should bar the MIL and codes.

 

No, its not a trick question, the car has now passed its MOT, so it can be taxed, the MOT lasts for 12 months, so you don't have to worry about emmissions etc untill then
All the EML is is a light on the dash - as long as the car starts and runs it does not matter, ditto the fault codes

its an 11 year old car - you may get another year out of it without spending any more money on it - then you can drive/ tow it to the scrappies and get your £200 when the MOT runs out next year

then you can buy a "perfect" car (if such a thing exists) - even a brand new car can (and does all too often) have faults

who cares if there ar 4, 40, 400 or more fault codes and a little light on on the dash?

 

the codes tell you something is wrong, why would I want to ignore them and run the possibility of something catastrophic happening to the engine when I have no money to buy another engine or another car?