oxygen sensor yes OR no ?
 

oxygen sensor yes OR no ?
I Have A 87 R10 Pick Up With A 5.7 TBI In Her, It Have No Cats
My Question Is Do I Really Need The oxygen sensor
Some One Put Duels On Her, No Y pipe Just Straight Back

And I Only See One oxygen sensor On Drivers Side And The Code Is 45 On OBD1

Need A Little Help In This Matter
Thank You
Harley03joe :smoke: :smoke:

Re: oxygen sensor yes OR no ?
 

you absolutely need the O2 sensor. The ECM reads the 02 Sensor and calculates the proper fuel to inject in closed loop mode. Without it the ECM can not make adjustments to the fuel injection rate.

Re: oxygen sensor yes OR no ?
 

Code 45 is rich. Check fuel pressure, leaking injectors, etc...

Without the O2, the engine will never go into closed loop and you will have poor performance and mileage.

Re: oxygen sensor yes OR no ?
 

Thank You Guys For The Info

Tell Me Where The Wire Is That Is To Be Disconnected When Checking Timing
On My 87 Chevy Silverado 5.7 EFI Color And Location A Picture Would Really Help Out

Thank You In Advance
Harley03joe :smoke: :smoke: :smoke:

Re: oxygen sensor yes OR no ?
 

I'm not sure if an 87 has a heated O2 or not, but if it doesn't they seem to run better to me converted to heated.

Re: oxygen sensor yes OR no ?
 

What Is A heated O2 ??
Thanks
Harley03joe :smoke: :smoke: :smoke:

Re: oxygen sensor yes OR no ?
 

A Heated O2 Sensor can heat itself, while the stock O2 sensor relies on the engine heat to heat it up.

You said someone put dual exhaust on - did they remove the factory manifolds and replace with headers? I ask because the 02 Sensor goes into the manifold, not the Y-pipe. If you still have stock manifolds you should have a port for the 02 sensor.

Re: oxygen sensor yes OR no ?
 

Should be a brown wire with a black trace. It will be taped to the outside of the loom just below the steering column in the engine compartment.

Re: oxygen sensor yes OR no ?
 

Just to add a bit more detail...

The heated sensor will also get the system into closed loop faster, which can have a positive impact on mileage. If the O2 has been moved downstream from the manifold, such as into the Y-pipe, then a heated setup is almost mandatory as there isn't enough heat left in the exhaust to get the O2 to work reliably.

I converted mine to a heated setup although I still have stock manifolds. Super easy to do. Heated sensor has 3 wires - one goes to the stock wire in the harness, and the other two are power and ground. Just use a keyed power source.

Re: oxygen sensor yes OR no ?
 

FYI , My 87 is a NON Heated O2 sensor (single wire)

Its on my to do list to convert it to heated, Life got in the way.

DieselSJ , does it run better after you modification?

Re: oxygen sensor yes OR no ?
 

I'd say it was worth the effort. I don't have any data logs from back then, but it almost seemed as if it would fall out of closed loop whenever I decelerated. It would almost stumble a little when I got back on the throttle after decelerating to a stoplight, and that totally went away. Seat of the pants it just feels smoother. Plus I used to have mileage that would swing between 8-11 and now it has settled into a pretty constant just over 10. When I had it smogged earlier this year and they ran it on the rollers, the tech commented that it was the smoothest running big block he has had in there.

Re: oxygen sensor yes OR no ?
 

Re: oxygen sensor yes OR no ?
 

Re: oxygen sensor yes OR no ?