Have fitted full de cat system, the down pipe has a location for a Lambda but I currently have it blanked off.
Is this the correct thing to do ?? any dangers of damaging the engine what does it do to the mixture etc etc. Any advice welcomed.

 

Me thinks this may give you idle - low rev problems.

Under load (revs) - WOT the ECU only uses the MAF for fuel calibration - however at low load idle etc Fuel is calibrated by the lambda sensor.

Personally - I'd recommend you refit it - you are more than likely to get a CEL error.

Chris

 

generally speaking if you disconnect a lamda sensor a car's ecu will fall back to a get you home setting ie safe but very inefficient and lower power. also if the cars modded, it may not even be safe

 

Depends on where your lambda was pre-decat.

All decat pipes has a hole for the lambda sensor to cater for the sensor position on the later cars (MY98 on IIRC) but the earlier cars had the sensor in the headers, so the hole needs to be blanked off. If your sensor was already in the catted DP then you will have a problem. If however it wasn't there in the first place then what you have done is fine.

Justin

P.s. If you do have an earlier car the best thing to do is to move the sensor to the DP (it just about reaches) and blank off the hole in the headers.

 

Just adding my support to Jay - I had assumed you had just removed the lambda sensor from the downpipe - if the Lambda sensor is still in place fitted in the header then there's not a problem in blanking off the hole that is not used in the downpipe.

[Edited by Chris.Palmer - 1/15/2003 1:52:38 PM]

 

The car is a 93 WRX Ra, apparently it has two sensors, one that sits in the exhaust under the front of the engine and one that sits after the cat, when I fitted the new down pipe it has a place for a lamda that sits much higher up behind the turbo, that's the one I didnt bother with and just blanked the hole.
Hope that helps to clarify things. The car runs fine and you can notice a large increase in performance. Just worried about long term affects.

 

What you've done is fine. The sensor you describe that sits after the cat is just a temperature sensor, warning that the cat is too hot, now that you don't have one that sensor is no longer required.

Justin

 

Many thanks to all who responded, you have been a great help.