Oxy sensor location 88 TBI 350

[legionwagon]

Folks,

I've got a transplant patient with a 350 TBI setup that is running poorly at light throttle (surges). It's from an 88 350 TBI truck. I am getting funny readings on the oxygen sensor (lots of variation and changeovers), which is in the exhaust manifold. On a normal truck, where is the sensor located? If on the pipe, about how far down the pipe is it located? Is it before or after the pipes join together (if they do join)? Thanks for your help.

[SPARK CHASER]

Folks,

I've got a transplant patient with a 350 TBI setup that is running poorly at light throttle (surges).  It's from an 88 350 TBI truck.  I am getting funny readings on the oxygen sensor (lots of variation and changeovers), which is in the exhaust manifold.  On a normal truck, where is the sensor located?  If on the pipe, about how far down the pipe is it located?  Is it before or after the pipes join together (if they do join)?  Thanks for your help.

 

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Oxygen sensor should be located on driver's side exhaust manifold just above where exhaust pipe mounts.

[legionwagon]

Folks,

I've got a transplant patient with a 350 TBI setup that is running poorly at light throttle (surges).  It's from an 88 350 TBI truck.  I am getting funny readings on the oxygen sensor (lots of variation and changeovers), which is in the exhaust manifold.  On a normal truck, where is the sensor located?  If on the pipe, about how far down the pipe is it located?  Is it before or after the pipes join together (if they do join)?  Thanks for your help.

 

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Oxygen sensor should be located on driver's side exhaust manifold just above where exhaust pipe mounts.

 

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Now that's on a TBI (twin drooling injectors), not a multiport injection?

[thecraft]

I thought it was located just before the cat converter...

[legionwagon]

I thought it was located just before the cat converter...

 

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Any tie-breakers?

This is just a guess as to why my car is surging, since there seems to be something funny about the Oxy readings- they jump wildly up and down, not just varying a little above and below an average reading. From 4 to 700 mv in a second. I thought that maybe some computers (MPI vs computer carb vs. TBI) were calibrated for the exhaust manifold location (varies more), and some were designed for further down the pipe (more steady). Just a guess. Any more votes as to the official place for a TBI setup?

Thanks!

[6.0LOUIS]

THE SENSER IS ON THE LOWER END OF THE DOWNPIPE I JUST REPLACED MINE ON AN 01

I thought it was located just before the cat converter...

 

<{POST_SNAPBACK}>

 

 

 

Any tie-breakers?

This is just a guess as to why my car is surging, since there seems to be something funny about the Oxy readings- they jump wildly up and down, not just varying a little above and below an average reading. From 4 to 700 mv in a second. I thought that maybe some computers (MPI vs computer carb vs. TBI) were calibrated for the exhaust manifold location (varies more), and some were designed for further down the pipe (more steady). Just a guess. Any more votes as to the official place for a TBI setup?

Thanks!

 

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[ZZ327]

ive got a 88 TBI 350 silverado

 

the sensor is located on the drivers side exhaust right after the manifold, you can reach and see it under the hood.

 

If youre surging you might wanna check out the EGR valve behind the Throttle body on the intake, I replaced a lot of crap on mine before I figured out the EGR was causing it!

[legionwagon]

ive got a 88 TBI 350 silverado

 

the sensor is located on the drivers side exhaust right after the manifold,  you can reach and see it under the hood.

 

If youre surging you might wanna check out the EGR valve behind the Throttle body on the intake, I replaced a lot of crap on mine before I figured out the EGR was causing it!

 

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Thanks for the info; I won't bark up that tree (relocating the oxy sensor.) I'll look at the EGR; it seems to work, but maybe it's on too much or something. I tried disconnecting it once with no changes, but that was a while back when I was just looking at the issue. Any other hints would be appreciated.

Thanks again.

[getcrunk88]

is it doing this at idle also?

[legionwagon]

is it doing this at idle also?

 

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Idles a little low, stalls occasionally, but I figure that is either a small issue with the IAC valve, or something else minor. Fortunately I don't use the car every day; it's the camper puller and general back-up vehicle. Seems to run better in this cooler weather, and also does better (power) when in open loop when it first starts up. Main issue is at cruising speed under light acceleration, surges and chokes consistently. More gas and it does fine.

Thanks for asking, any hints appreciated.

Haven't spent time on it lately, bigger fish to fry.

thanks.