I'm faced with having to fit a new downpipe this weekend. The Dealer can't fit a new Lamda until Tuesday next week, so naturally the want to do both and charge for that pleasure.

What problems would I get if I changed the downpipe and left the Lamda off the car (I'm thinking of fitting a proper TSL plug for the Lamda boss), then drove the car to the Dealer?

Stefan

 

I'm not sure how the ecu deals with a lambda failure - I'd guess CEL and it will use maps for fuelling at low load/revs (remember, lambda is only used by ecu for closed-loop fueling - when you gun it, it reverts to the maps).

However, it might go into limp-home mode which means low boost - doubt it though, as this would exascerbate (sp? lol!) the problem.

<joke mode-on> Best just to leave TSL at full boost and keep it that way 'til you get to your dealer

Richard

 

Cheers Richard.

Keeping the car on full chat does sound like a better option

The Lamda was only reading 0.3 volts steady (no fluctuation at all)and looking at the tailpipe, it's running pretty rich.

If it only uses it on closed-loop idle, then it sounds safe enough.

I have until the weekend to decide, so if I hear any horror stories, I'll let the dealer do both.

Stefan

 

I thought when the lambda sensor fails it just runs rich all the time.

All the old cars had the sensor in the headers whuich caused them to over heat and often fail.

i ran with a fecked lambda sensor for thousands of miles, it just runs it rich for safety.

Best bet when refitting these cars to to refit it in the downipe aperture.

 

Is it okay to fit a new sensor (say Hotwires one from Halfords) where the exhaust temp sensor is on the downpipe on Pre 97 cars & just leave the old sensor in the headers & just cut the connector.

Does the temp sensor in the downpipe do anything?

Johny.

 

Mine failed and when Subaru checked it on the Select, it had gone into a safe mode

My fuel consumption was a bit crap, so must run rich...

MB

 

The temp sensor is there to check if the cat is at operating temperature. If you fit an aftermarket downpipe at teh same time, there will be no cat to check on.

You can leave the sensor in the headers, but you could also buy a blocking boss, I think scoobysport may have some of these, as it will present less restriction.

I am sure difference will be marginal, but if you would ahve neede to change it anyway, it may be worth the effort to do it properly.

The new sensor will certainly last much longer in the downpipe, and if you fit a bosch LSM 11, it is a sturdier sensor anyway. It also has temperature compnesation so will give better readings at very high egts.

 

My car's a MY99 RB5 if that makes a difference?

It's only going to be run without the Lamda on Monday and Tuesday morning to/from work (so probably 60miles tops).

Stefan

 

I have just re read what you are actually asking.

Is your car still under warranty? cos if not, get yourself a proper downpipe!

you will be okay fitting the buggered sensro back in for a few days (to my knowledge) but ask the dealer if in doubt. Get them to plug in the select monitor and see if a fault code appears for the lambda sensor (not sure if one exists).

Fitting the lambda sensor once it arrives is something youc an do yourself with ease, you just need a large enough socket.

It can be reached (unless the top mount is in the way (cant remember as have had a fmic for too long).

Wait till car is cold, unplug, unscrew, screw in and re plug. simple.