Integra DC5 emissions fail
Discussion
I did put this in the Honda forum but had no replies.
Done the MOT a couple of weeks early on the Integra today, all was well bar a numberplate light and sidelight bulb and the emissions. The CO readings are extremely high, just over double what they should be, the car still has the standard cat in, I've done a check tonight but no error codes are showing up for the o2 sensors.
Any educated guesses what the issue might be?
Dan
Done the MOT a couple of weeks early on the Integra today, all was well bar a numberplate light and sidelight bulb and the emissions. The CO readings are extremely high, just over double what they should be, the car still has the standard cat in, I've done a check tonight but no error codes are showing up for the o2 sensors.
Any educated guesses what the issue might be?
Dan
This might sound silly, but did you give the car a good thrashing before getting it MOT'd?
The only reason I ask, is because I also drive a VTEC Honda (Although only a 170hp DOHC model...wish it was a type-r!
). If I pootle along to the MOT station and it goes straight on the emissions reader, the CO is almost double just like yours. However, if I give it a good beating on the way there engaging VTEC often and then letting it settle for 2 minutes, this seems to help as the readings then become incredibly low. Maybe you could try that?
Apart from that, I can't think of what else to suggest really! I assume the car is cared for in terms of servicing? Are you sure the cats are original and not cheap replacements?
The only reason I ask, is because I also drive a VTEC Honda (Although only a 170hp DOHC model...wish it was a type-r!
). If I pootle along to the MOT station and it goes straight on the emissions reader, the CO is almost double just like yours. However, if I give it a good beating on the way there engaging VTEC often and then letting it settle for 2 minutes, this seems to help as the readings then become incredibly low. Maybe you could try that?Apart from that, I can't think of what else to suggest really! I assume the car is cared for in terms of servicing? Are you sure the cats are original and not cheap replacements?
Tried the emissions test twice, went and gave the car a good pasting the second time but it made no real difference. Cat looks original when I've been under the car before so as far as I know it is. Other than that it's serviced when it needs to be, oil changed regular etc. Last service was only about 6 weeks ago and that included new plugs aswell.
Have you checked the EML bulbs are still in place? If a previous owner has decatted it then it's possible they removed the bulbs on the dash to stop the warning light from showing. AFAIK, on a newer Honda you can use a function of a Kpro ECU to disable the light, or fit a spacer and an O2 sensor to the cat to stop the light from going off. The cheapest and easiest (and worst) option is just to pull the bulb though. Check it illuminates when you turn the ignition to the first position to see if the bulb is there or not.
If the bulb is gone, you might have a failed O2 sensor, which iirc was a common problem on the older Integras, I've heard nothing regarding the newer ones though. If the O2 sensor was fried it would perhaps cause the car to run exceedingly rich, but you'd expect a warning light too.
If you have to source a new cat, you'll have to get one from a breakers more than likely, as Honda charge a stupid amount for the car (over £1500 new iirc). It would be cheaper to buy a sports manifold and Hondata ECU + a remap than it would to buy a new cat, and you could use the change left over to ingratiate yourself with an MOT tester who might be willing to sidestep the emissions test
If the bulb is gone, you might have a failed O2 sensor, which iirc was a common problem on the older Integras, I've heard nothing regarding the newer ones though. If the O2 sensor was fried it would perhaps cause the car to run exceedingly rich, but you'd expect a warning light too.
If you have to source a new cat, you'll have to get one from a breakers more than likely, as Honda charge a stupid amount for the car (over £1500 new iirc). It would be cheaper to buy a sports manifold and Hondata ECU + a remap than it would to buy a new cat, and you could use the change left over to ingratiate yourself with an MOT tester who might be willing to sidestep the emissions test
EML comes on everytime I turn the ignition on, it's one of those things I always look for when I first get in the car. No idea why I do it to be honest. Spoken to a mate/mechanic tonight, he's fairly sure it'll be the cat if it's just the CO readings that have failed and there's no EML or any error codes showing up. Does seem the most likely solution. Good thing is there are a couple on ebay at the moment for sale.
That's very strange. As you probably know, a high CO reading means the car is running too rich, which could mean anything and everything could be broken or defective. Vacuum pipes leaking - Multiple chances of dodgy sensors - restriction somewhere on the intake system. They are just a few possibilities!
Also, I know you said the car threw up no fault codes or EML's, but don't take that as a guarantee that everything is well with the sensors and electronics. My Accords O2 sensor on the downpipe failed (common on 6th gens), but didn't give me an EML until I drove it around 100 miles. I only knew something wasn't right beforehand as it was drinking a lot more fuel. If it wasn't for that, I wouldn't of known as it still drove fine and pulled hard etc.
Dan, I'm going to get some shut eye now pal. If you can, type up the exact figures of all the readings (not just the CO) and the RPM. I will take a look in the morning/afternoon and see if I can help in any way.
Also, I know you said the car threw up no fault codes or EML's, but don't take that as a guarantee that everything is well with the sensors and electronics. My Accords O2 sensor on the downpipe failed (common on 6th gens), but didn't give me an EML until I drove it around 100 miles. I only knew something wasn't right beforehand as it was drinking a lot more fuel. If it wasn't for that, I wouldn't of known as it still drove fine and pulled hard etc.
Dan, I'm going to get some shut eye now pal. If you can, type up the exact figures of all the readings (not just the CO) and the RPM. I will take a look in the morning/afternoon and see if I can help in any way.
it's running slightly lean (lambda 1.04) but has too high a CO.
this would say to me that the exhaust has an air leak in it somewhere BEFORE the primary lambda sensor.
I would suggest the sensors working as the results look consistent, and if it wasn't, the MIL would be on
CAT could be fubar, but I don't think so from the numbers on the slip, first thing is to work out wht the lambda reading is lean, and sort that, then read the HC and CO, if the lambda is in target and the CO is way off, then the CAT is either cold or fubared.
this would say to me that the exhaust has an air leak in it somewhere BEFORE the primary lambda sensor.
I would suggest the sensors working as the results look consistent, and if it wasn't, the MIL would be on
CAT could be fubar, but I don't think so from the numbers on the slip, first thing is to work out wht the lambda reading is lean, and sort that, then read the HC and CO, if the lambda is in target and the CO is way off, then the CAT is either cold or fubared.
From what I've managed to dig up from forum searching and various other sources this morning it seems to be more of a cat issue. A few people all said the same thing, if the readings are that far out due to a sensor the eml should be on because it will have failed. Need to get it on a ramp I think and check to find if there's any leaks.
Dan, this is the problem with posting stuff like this on the interwebs...You get people saying it's running lean even though the MOT slip says otherwise.
Usually, when the emissions are high, you get a low lambda reading. When the emissions are low, you get a high lambda reading. Your car is strange, because everything is high! The HC is through the roof, as is the CO. The lambda seems to be working well, as it's picking up the high pollution rates.
I've had a look, and from looking at those figures, suggests it's burning oil. If it is burning oil, I would say it's the piston rings as the emissions are high during a fast idle test.
Maybe try doing a compression test Dan.
Usually, when the emissions are high, you get a low lambda reading. When the emissions are low, you get a high lambda reading. Your car is strange, because everything is high! The HC is through the roof, as is the CO. The lambda seems to be working well, as it's picking up the high pollution rates.
I've had a look, and from looking at those figures, suggests it's burning oil. If it is burning oil, I would say it's the piston rings as the emissions are high during a fast idle test.
Maybe try doing a compression test Dan.
I'd go for cat, lambda is very slightly high which could indicate an air leak somewhere on the exhaust system but that doesn't explain the high CO and if the engine was genuinely running rich the lambda would be running low not high anyway.
Swap the cat for a known good one (lots of new and second hand cr@p out there) and make sure the exhaust joints are well sealed.
Swap the cat for a known good one (lots of new and second hand cr@p out there) and make sure the exhaust joints are well sealed.
remove all remanents from the old cat, then put it back on... kepp the new cat safely wrapped up in the garage, packed with silica gel.
their expensive, fail, and stunt performance.. just keep swapping it every MOT.
if you de-coke it after every use you'll be able to sell it as-new later down the line
their expensive, fail, and stunt performance.. just keep swapping it every MOT.
if you de-coke it after every use you'll be able to sell it as-new later down the line
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