So I\'m in Belgium and we have some kind of MOT here as well, only a bit more strict then lord knows wehere in the world.
Got up this morning at 6 to be the first at the MOT post.waited for half an hour and then...
Red card...
Why? Lambda value to high. measurement shows 1.4 (don\'t know the unity) and should be around 1
My car is 100 stock except for a greddy BOV and Pettit AST.
Has 111000kms on the clock (engine 66.000), exhaust all stock cats (originall backbox replaced in 2002 and 500kms driven since then)
Need to add that the check point is only 2kms away from my home, so I just got the car warmed up at max 3000rpm and had it at idle before rolling into the MOT. Maybe I just have hit the gas a few times to have some flow through the exhaust and the airpump on decently.
My next concern is the HKS downpipe I will be installing. Will it affect exhaust pollution in a bad way?
Any thoughts are welcome.
I think I\'m going to put a new lambda sensor in as well (or should I clean it?)
Thanks
Neal
With an Apexi Power FC/Other EMS, you can fiddle with it to get a better reading, but nothing beats good compression! A number of times when I have been down a RxMotors, cars that have just been built end up going for an MOT while they\'re with us and they don\'t even move the gauge they are so clean. Good plugs will go some way to helping but not all the way, are you convinced the air pump is working and the air filter is clean? Wouldn\'t have thought the downpipe would drasticly effect emissions, but I wouldn\'t put it on a car without an Engine Management System. That\'s all I know about that, sorry if none of it\'s any use. Good Luck
thx
spark plugs were swithch at 107.500km
at what RPm or any other trigger does the airpump come in actually?
change the lamda sensor in the downpipe they do wear
For the airpump to switch in the engine needs to be running at 3000rpm. usual speed for the test here in Blighty is 2500rpm. If the tester tries to do the test at 2500 then the airpump is on the vergie of eing on and it makes the engine blubber as it come on and goes off. Once over about 2700 it\'s fine and running proper.
Mind you , a high lambda reading points to a lean mixture (too much air) which could indicate an air leak. Lambda reading is 1 for stoichiometric air/fuel mix , higher than one for lean mix and below 1 for rich mis.
I\'m on my quest to change al hoses on the engine with upgraded ones. So in time I will have found the issue, if there even is one..
But I think you answered the issue right here.
Like said, I drove it from home to the checkpoint at max 3000rpm to let it warm up, then arrived at the station and let it idle for about 20-25minutes, then drove in, meter in the pipe then the guy told me to rev it to 2500rpm steady so I guess the airpump never had the change to do its work.
Hi Neal..
will try to keep this short!...
I had a problem passing my test last year. Mod\'s: aftermarket Intake, Dp, High-Flow Cat, Catback exhaust and PFC... I failed with Lambda reading at 0.820. What I found, my PFC could not run my air pump correctly. It should shut off at 3250 rpm, mine stopped between 2700/2800 rpm and came back on at 2490/2500 rpm. So, trying to hold 2500 rpm\'s for the test, resulted in my air pump clicking on and off and rpm\'s bouncing around. I spent sometime trying to correct the problem with the magnetic clutch/ ap relay, etc... and fuel adjustments with the PFC... nothing worked.
So, I took the PFC out and installed my stock ECU. Now my airpump is working correctly. No bouncing rpm\'s and shut\'s off at 3250 and runs under 3200, but my a/f ratio\'s are 1.4- 1.5 like yours. All my testing with the pfc and stock ecu, the car had been running for a long time and the cats were plenty hot. I did not find any air leaks when I tested my exhaust system but I did notice a big difference if I shut the motor off for only a minute or two. You have to get the cats hot and not let them cool anytime before the test.
Now that I have switched from the PFC back to stock ecu, I need to get the Lambda down. I started to add electric load to the motor. First the AC... soon my Lambda came down... then my lights, radio, defroster, anything I could find! ha....:rollin
The best Lambda reading I could get was 1.046. Here in Denmark, you need to be between 0.970 and 1.030. The next day I retested and they passed me. I can\'t say this will work for you but it\'s worth a try.
Check your air pump and make sure it engages correctly and it pumps air. Then find a local smog tester and try adding electricl load.
crossing my finger :)
Oliver