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73-87 Chevy _ GMC Trucks => Performance => Topic started by: Whodatjrock on April 13, 2010, 04:22:49 PM

Title: O2 sensor simulator.
Post by: Whodatjrock on April 13, 2010, 04:22:49 PM
Ok, I saw a post about after cat sensors. My question is, the o2 sensor that was connected to my exhaust manifold is just sitting by my valve cover. My check engine light comes on after about 5 minutes of driving. My gas mileage is horrible after the headers were put on. What kind of simulator do I need or can I just remove the whole sensor. I seen a couple of simulators but have no idea which I need. I have a 87 silverado w/ 5.7 350 tbi. I have no cats.
Title: Re: O2 sensor simulator.
Post by: VileZambonie on April 13, 2010, 04:30:34 PM
The post Cat O2 simulator was what we were talking about. If you have a tbi system you need to hook up the O2 sensor. Just get a bung and put the sensor back in. You can get an O2 bung for less than $4.00
Title: Re: O2 sensor simulator.
Post by: Layne on April 13, 2010, 06:02:04 PM
*Curious* Why is the O2 in the drivers side bank, as opposed to the 88-98's is after the Y pipe? Would the passenger bank run EXACTLY the same as the left?
Title: Re: O2 sensor simulator.
Post by: Irish_Alley on April 13, 2010, 06:13:14 PM
I would assume it would be cause of the efi since each injector goes to each cylinder while your truck if it has a tbi its only two injectors
Title: Re: O2 sensor simulator.
Post by: Blue 82 on April 13, 2010, 06:32:16 PM
The 88 and 89's are mounted on the drivers side manifold
My 94 has a 3 wire after the "y"
My 2000 5.7 has 4.
When I put shorty headers on my 89, I get an erratic O2 voltage reading at idle and around town but I get a decent voltage reading on the highway. Due to the mods I have done, it's running lean at anything over 30% throttle (but that's another story).
I'm guessing the O2 sensor is not getting hot enough at low speeds/load.
I have a spare 3 wire (heated) O2 sensor from my 94 that I'm going to install in the 89.
I just need to find a factory style connector to make it happen.

You can mount the O2 sensor after the Y, just extend the wire.





Title: Re: O2 sensor simulator.
Post by: Layne on April 13, 2010, 07:16:24 PM
I have these- http://www.jegs.com/i/Flowtech/387/91830/10002/-1
Just curious. Thanks guys.
Title: Re: O2 sensor simulator.
Post by: VileZambonie on April 13, 2010, 07:28:48 PM
Irish is correct. The O2 is only valid if everything is working correctly. Being a dual plane TBI system it would read the same. The O2 sensor isn't designed to compensate for errors and is only efficient if the engine is operating as designed.

Zirconia O2 sensors need about 600°F to wake up and start functioning hence why they put them as close to the engine as possible.

On my Mutt I welded a bung in the Header reducer. If anyone wants to see pics I'd be happy to take them.
Title: Re: O2 sensor simulator.
Post by: Whodatjrock on April 13, 2010, 08:16:21 PM
Thanks, I have ceramic coated headers. Should I put a hole in the headers or can I extend the wires and put the bung on the pipes?
Title: Re: O2 sensor simulator.
Post by: VileZambonie on April 14, 2010, 07:25:56 AM
Put it in the reducer