o2 simulator question.

[98gpking]

ok ive scanned my PCM for hard and soft codes, ive done a bunch of custom tuning to the PCM, ive done a complete tune up using only the parts everyone told me. and im still only getting like 150 miles per tank (mpt) i know this is wrong. even in my trans am with 340 horses i was doing better.

my question is. maybe its my 02 sensor thats acting funny. but im not sure if its the front one on the manifold or the one behind the cat. according to www.zzperformance.com they say the one behind the cat has nothing to do with the PCM or the with the way the car really runs pretty much its just there to let you know your cat is good or not. so im thinking its the one on the manifold. but everyones telling me to swap out the one behnd the cat

im gonna do the u-bend and resonator delete and just take out the rear 02 anyways. and just add the delete. but can i remove both of them and just put 2 simulators in my car or will that be bad

i figure the simulator would be best because its always giving a perfect reading.

[BNaylor]

The key O2 sensor is the one before the CAT and they will degrade over the years. This is the one that controls emissions and helps keeps the air/fuel mixture ratio at that ideal 14.7:1 in the PCM closed loop mode of operation. You cannot use a simulator on that one. The rear 02 sensor monitors CAT converter efficiency and you can use a simulator there.

How is your highway mileage which is the best way to determine whether the front O2 sensor is operating efficiently. Best way to check an O2 sensor is with a scanner capable of checking O2 operation. Or you can remove the sensor and try cleaning it. Make sure there is no carbon build up in the vane directors.

[98gpking]

60-70 mph is when i get my best MPG its around 26 at its highest. anything above 70 it just slowly crawls down to below 20.

so what your saying the best thing to do is replace the one on the manifold with a new one, and simulate the one in the u-bend?

[tblake]

Yeah, your not getting very good milage at all. If I fill my GTP up and take it for a trip of constant highway speeds, I've seen highest MPG around 31 or 32, and town driving i usually get around 22-23.

[BNaylor]

Originally Posted by 98gpking

so what your saying the best thing to do is replace the one on the manifold with a new one, and simulate the one in the u-bend?

If this is a daily driver or used mainly on the street then I would replace the front O2 sensor if the cleaning doesn't help. Be sure to use the AC Delco AFS109 only. No Bosch, Denso or other aftermarket brands.

The only time an O2 simulator is needed is when you delete the CAT Convertor or have a problem with an aftermarket CAT triggering the P0420 DTC which is CAT efficiency, otherwise it is just a waste of money, time and effort.

[98gpking]

Originally Posted by BNaylor

If this is a daily driver or used mainly on the street then I would replace the front O2 sensor if the cleaning doesn't help. Be sure to use the AC Delco AFS109 only. No Bosch, Denso or other aftermarket brands.

The only time an O2 simulator is needed is when you delete the CAT Convertor or have a problem with an aftermarket CAT triggering the P0420 DTC which is CAT efficiency, otherwise it is just a waste of money, time and effort.

so what should i clean it with...just like a toothbrush and some mild hand soap or a pipe cleaner. i obviously dont want to damage it

[BNaylor]

You can use any cleaner that is "oxygen sensor safe". Throttle body or carb spray cleaner, fuel injection system cleaner. Toothbrush will work to get any carbon deposits off, if any. Important part is to make sure there is no carbon blocking the vanes. After cleaning hold the sensor up to a lighting source backdrop and then visually inspect.