Emissions Issue

[bigvinny]

I checked my emissions today and found that the Lambda reading is not at it's optimum (lowest reading was 1.15, limit is 1.03). HC & CO readings are normal. Has anyone else experienced the same, perhaps whilst presenting for an MOT, etc. Any advice would be helpful.

Thanks.

[ChrisW]

Mine's a bit different - I've got slightly high lambda (1.063) and high CO (0.973%). HC was within limits but might be a bit high at 155ppm.

I suspected lambda sensors and changed the two main sensors (before the cats) but that made no difference. Maybe I should have done the secondary sensors as well. My current suspicion though is a cracked EGR pipe.

[Ruud]

Mine's a bit different - I've got slightly high lambda (1.063) and high CO (0.973%). HC was within limits but might be a bit high at 155ppm.

I suspected lambda sensors and changed the two main sensors (before the cats) but that made no difference. Maybe I should have done the secondary sensors as well. My current suspicion though is a cracked EGR pipe.

If you have a cracked EGR pipe you should also hear it.

I've fixed mine a few weeks ago (2 big cracks at the harmonica bit) and she ran a LOT quieter :)

[Manc]

Where is this pipe and how much was the job?

I can hear it like my exhaust is blowing, or a bit more of a V8 grunt , but it can sound more like blowing when near walls or fences (confined space is the word).

My emissions failed and i heard here that the sensors sometimes made no difference..........

It sounds like its the back of the engine when the bonnet is up (when the struts will hold it up :tsktsk: )

Just faint blowing but defo not normal, im now suspecting this pipe...........

[Ruud]

Where is this pipe and how much was the job?

I can hear it like my exhaust is blowing, or a bit more of a V8 grunt , but it can sound more like blowing when near walls or fences (confined space is the word).

My emissions failed and i heard here that the sensors sometimes made no difference..........

It sounds like its the back of the engine when the bonnet is up (when the struts will hold it up :tsktsk: )

Just faint blowing but defo not normal, im now suspecting this pipe...........

The pipe goes from the back of the intake to the exhaust pipe almost under the car...the harmonica bit is about halfway

I've managed to weld it but I don't know how much of a welder you are..lol

some say it's a 3 to 4 hour job...I've managed to get mine off, welded and put back again in about 90 minutes :)

[ChrisW]

Having just been underneath the car with the engine running I've discovered exhaust gas leaking from the rear flanges of both cats. So maybe I'm barking up the wrong tree with the EGR pipe - although I've already bought a new one from Lexus!

Obviously I should unbolt the cats and replace the gaskets but everything's so rusty round there, I might just try sealing it with some Gun Gum for now.

[sir john]

i have the same problem with my exhaust. Leaking from the rear flange of both cats. And mine are so rusted that the faces of the flanges have rotted away to the extent that they only meet where the bolts hold the joints together. I say bolts, they are no more than pointy bits of metal. I tried Metal Putty. Its a 2 pack thing you get from Halfords etc. it works for a bit then breaks up. Ive also tried Gun Gum. Same thing.

The whole system really needs taking off (cutting disc the "bolts" off) and new flanges welding on. Probable to cats and exhaust pipe flanges. Has anyone tried this?

Dont want to replace the whole lot as only the joint is shot and the system is Toyota stainless steel exhaust system.

PS. i have alraedy bought the new gaskets from toyota. £4.11 each. ... Quality!

[Monster-Mat]

The whole system really needs taking off (cutting disc the "bolts" off) and new flanges welding on. Probable to cats and exhaust pipe flanges. Has anyone tried this?

i had to remedy the exhaust on the GS, this way....

[simontaylor]

My flanges were leaking on my LS400.

I used gun gum type paste and then used a massive jubilee clip and tightened it up around the flange joint to hold the gun gum in.

At MOT time, after it had held fine for a year, I just loosed the jubilee clip and re packed some more paste in to the joint.

WOW, so much quieter afterwards.

[steve2006]

Mine's a right mixture, the exhaust piping is stainless steel but not sure about the boxes and with no requirement for it in Japan no EGR system is fitted, this made the starter motor job a little easier.

If anyone needs the EGR gaskets I bought before I realised PM me ( mods not selling giving away) :D

[Manc]

Mine's a right mixture, the exhaust piping is stainless steel but not sure about the boxes and with no requirement for it in Japan no EGR system is fitted, this made the starter motor job a little easier.

If anyone needs the EGR gaskets I bought before I realised PM me ( mods not selling giving away) :D

I think i might take those off your hands, i was going to do my egr pipe later this year.

But i have noticed air coming out before the cats on both sides (same point), when i sat in my seat and looked underneath once

saying that, i had to replace the gaskets near the front last year so the rear ones should be worse as they are more exposed to the elements....

but get in touch and i'll make sure i'll pay the postage :winky: