Second Lambda sensor?

[Henny 0]

Hi Guys,

 

Here's an interesting one for you... On a G60 there's a pipe that runs from the exhaust manifold into the engine bay with a blanking plug on the end... It's there so that VW can test your emissions before they go through the cat...

 

What I want to know is:

 

Does anyone know any reason I can't take this pipe off completely and put a second Lambda sensor in there to run an Air/Fuel gauge from? I could even put in a wide band one then and get some nice readings rather than the fluctuating ones you get when tapping onto the ECU's Lambda...

 

 

Anyone know?

 

Cheers 8)

[andycowuk 0]

i did away with it when i changed my manifold. So there is no reason you cant change its purpose!

 

Not sure how you wouldget a probe in there, but thats anotherquestion!

[GazzaG60 0]

but why?

 

you wanna know what the engines doing not what a different sensor is telling you..unless its wideband of course.

 

You dont want one sensor telling you its fine if the proper engine one isn't. its the proper one that the readings are used from.

[Henny 0]

you don't get a true reading from the one the ECU uses due to the ECU screwing about with it all the time... An independent lambda should give me a proper reading of what the exhaust gasses are comprised of, and therefor what the engine is actually doing, not what the ECU is upto... surely that's what an A/F gauge is for isn't it?

 

Or am I barking up completely the wrong tree here? I'm confused... :?

[GazzaG60 0]

no your right you dont get a true reading you get a picture of vague engine working at stoich. from what i can gather from various sources inc SNS USA probly the people responsible for the amount of summit-racing AF gauges in G60s the AF gauge is good for telling u the following (not quotes)

 

1. proper lamba probe functioning

2. warmup status

3. WOT/idle swithc issues

 

to tell what is really happening you need a wideband as a O2 probe is onyl accurate at stoich, what its designed for.

to see whats-what at the ranges a wideband is needed. im thinking of fitting one too as the probe is same fitment, ill get a second nut welded on and fit it in there.

 

i use a mates wideband to set up. its amazing the differences in ration that cover one bar on a AF gauges especially at WOT

You might see 10,11 and 12 to1 on the wideband but itll have hit and held on the AF gauge.

 

my planis not the hijack the thread

 

use current summit AF for seeing the actual probe that the engine uses

fit a second NGK wideband probe(NGK does 8:1, bosch does 10:1 lowest) and fit a LM-1 (i think) from innovativeproducts.com to view ration info and graph for chip adjustments

[Henny 0]

8)

 

That's EXACTLY the kinda info I was after... 8)

 

Cheers Gazza... :D

[exturbo2003 0]

go with it henny i am gonna fit a second probe, already have a nut wielded in the down pipe, never thought of that hole, and will be getting a wideband too

let me know how you get on

[h100vw 0]

Only snag I see using the one on the manifold is, does it adequately cover all 4 cylinders???

 

When I fitted a boss in my MK1 to have a 5th injector(map fueller) fitted. The guy was adamant that it should go after all the cylinders come back together. I put it in after my 4 branch. He stuck a probe in the exhaust while setting up the map fueller. No idea if it was a wideband or not.

 

Personally I'd have it close to the ECUs probe.

 

Gavin

[Henny 0]

well, the pipe that is there at the moment is where VW test the exhaust for Lambda and CO content when the car has a cat to make sure it's running OK, and I can't see them putting a pipe like that in the wrong place... ;)

 

I understand what you're saying though... 8)

[bigtimeg60 0]

I need a new lambda sensor for my 91 g60 stage 4 charger any ideas on what the number would be coz everyone i have spoken to say there are about 3 or 4 different types cheers andy :(

[psykokid 0]

Only thought is that the lambda probe may be affected by heat. And there is certainly going to be much more heat at the exhaust manifold than right before the cat where the bung for the stock lambda probe. The 4 gas anaylzer that they use to test from that port works a tad differently than the lambda probe does.

[Henny 0]

Only thought is that the lambda probe may be affected by heat. And there is certainly going to be much more heat at the exhaust manifold than right before the cat where the bung for the stock lambda probe. The 4 gas anaylzer that they use to test from that port works a tad differently than the lambda probe does.

 

Now THAT is useful to know... 8) Thanks... I'll scrap that plan then and move onto plan B... ;)

 

Thanks psykokid 8)

[psykokid 0]

Only thought is that the lambda probe may be affected by heat. And there is certainly going to be much more heat at the exhaust manifold than right before the cat where the bung for the stock lambda probe. The 4 gas anaylzer that they use to test from that port works a tad differently than the lambda probe does.

 

Now THAT is useful to know... 8) Thanks... I'll scrap that plan then and move onto plan B... ;)

 

Thanks psykokid 8)

 

no worries mate.

 

also, if you get your hands on one of the innovate lm1 wideband units, you can pull the stock lambda sensor and drop the wideband in its place. The lm1 has an output that outputs the correct voltage for the cars lambda sytem to understand and make use of while still having a wideband lambda sensor hooked up. Plus you dont have to have any extra done to your cars exhaust (ie a new bug for an secondary lambda sensor)

[Henny 0]

damn! where did you come from with all this useful info??? 8) :lol:

 

That's what Plan B is... :shock: :lol:

 

Well that confirms that I understood how the Im1worked then.... I think I may have to invest in one.... 8)

 

Thanks again Psykokid! 8) :D

[aposegil 0]

anyone have a link or where to buy one of these LM1 wideband sensors :D

 

Not that i want to nick ur idea Henny :)

[psykokid 0]

damn! where did you come from with all this useful info??? 8) :lol:

 

here's a link to thier manual : http://www.innovatemotorsports.com/supp ... manual.pdf its on page 20.

 

it explains how to use the auxillary output in place of the stock lambda probe. you can use one of the other auxillary outputs to run an standard narrowband type a/f ratio gauge.

 

I had a problem with the a/f gauge that i was running introducing some sort of interferance into the signal wire making my car run very poorly. good ol picky digifant system. had to pull over on the side of the freeway last saturday on the way back from a GTG. clipped the signal wire going to my a/f gauge so that my car would run correctly. some stuff you learn the hard way..

[aposegil 0]

Just read the website and it says it runs a Bosch LSU4.2 sensor which can be picked up here in the uk, so do u need anything else???

 

also i heard that the g60 lambda works on different frequencies, so i.e u cant use a vr6 lambda on a g60 for example

 

How true is that

[psykokid 0]

Just read the website and it says it runs a Bosch LSU4.2 sensor which can be picked up here in the uk, so do u need anything else???

 

also i heard that the g60 lambda works on different frequencies, so i.e u cant use a vr6 lambda on a g60 for example

 

How true is that

 

you need the whole LM1 bit of kit to get it to work right, you cant just drop the LSU42 sensor in. It would be like talking to a cow in french... the lambda circut wouldnt be getting the correct voltage. LM1 box converts the LSU42 signal into something that the digifant ecu can understand. I dont know how picky MOT is over there, but as a cheap alternative to the $150 vw lambda probe we just get the bosch lambda probe for an 89 ford mustang 5.0 and hack off the ford connector and solder on the leads for the vw connector and heat shrink everything up and call it a day. $44 and a little bit of time versus $150. I'm sure you could just run some heat shielding tubing over the connections to hide them if thats an issue. most cars of that era use the same bosch lambda probe, the only difference being the connector that comes on it.

[PhatVR6 0]

Interesting. I run and AutometerA/F guage, and it bounces back and forth like a b4stard, annoying as f*ck. I was going to run a seperate probe for it too, but this new fangled thing sounds mint!

 

then again, I'm getting a cutum twin exhasut made up soon (one for each bank of cylinders) so I'm not sure what to do about the lambda setup now.

[Kevin Bacon 5]

Do you mean two seperate exhaust systems? I.e. one complete system for each of the two exhaust manifolds? So two 3-1 banks instead of effectively 6-2-1?

[PhatVR6 0]

yes, the front bank running a 3-1, and the rear bank running a 3-1 too, like a proper V exhaust should be.

 

The syncro sytsem is a twin exhasut all the way to the back box anyway, so I was going to dithc hte back bock and run 2 side exits, one on each side. I need a new downpipe, I cna't get anythign off the shelf to fit so I figured if I was getting one made I may as well get it done properly and go for a tubular header too. then this split banks idea came up so I figured I'd go for it. it should sound fantastic and hopefully if I can find somene who knows what they're doing, release some good power gains too. there's load of room back there to make seriously long primaries.