CA Emission Testing
Thread Starter
Intermediate
Joined: Jun 2010
Posts: 45
Likes: 0
From: Atascadero CA
CA Emission Testing
I have been reading for weeks on tuning, memcals, ECMs, etc. but haven't come across a clear answer to these two questions.
1. If you change the tune will it pass California smog test and can they tell that the prom has been changed without physically opening the ECM?
2. Installing a wide band sensor they recommend placing the sensor at least 16in to (preferably) 24in from the engine block and before the cat. There really isn't 16in from the block to the stock O2 sensor. Does the stock location work for wideband sensor?
1. If you change the tune will it pass California smog test and can they tell that the prom has been changed without physically opening the ECM?
2. Installing a wide band sensor they recommend placing the sensor at least 16in to (preferably) 24in from the engine block and before the cat. There really isn't 16in from the block to the stock O2 sensor. Does the stock location work for wideband sensor?
Burning Brakes
Joined: Mar 1999
Posts: 876
Likes: 9
From: Mooresville NC
1. If you change the tune will it pass California smog test
and can they tell that the prom has been changed without physically opening the ECM?
Installing a wide band sensor they recommend placing the sensor at least 16in to (preferably) 24in from the engine block and before the cat. There really isn't 16in from the block to the stock O2 sensor. Does the stock location work for wideband sensor?
If running headers, it is nice to have it in the collector insted of a single primary as in the single primary you are only seeing 1 cyl and you will get a much less smooth signal at idle as the 1 cyl goes through it's cycles..
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
The stock O2 sensor needs to be as close to the engine as possible. Note the location, which is right at the flange in the Y pipe. It needs to be HOT to work correctly. If the sensor is too far away it will never warm to operating temperature and the ECM will never go into closed loop mode.
As far as I know, all wideband sensors are heated, so you can put it anywhere you want.
As far as I know, all wideband sensors are heated, so you can put it anywhere you want.
