Getting 8.5 mpg need help

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JollyRoger01

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Can you graph data? Specifically B1S1 B1S2 B2S1 and B2S2. Monitor these 4 at OT in park at 2k rpm. No accessories on and turn all the lights off.
 
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BlueCollarTahoe

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Can you graph data? Specifically B1S1 B1S2 B2S1 and B2S2. Monitor these 4 at OT in park at 2k rpm. No accessories on and turn all the lights off.


You talking 02 sensors right? I did it for both ft/ and o2 sensors. Ftb1s1 and ftb2s1 are the only ones that were jumping. Sensor2 in both banks were flat. Don't think its giving any feedback
Now when I did the 02 sensors b1s1 was jumping. Bank1s2 was semi flat. Bank2s1 ans bank2s2 were jumping. Or are you talkinf about stft and ltft? Im in the car now so i can get realtime sata on what's needed and upload. I jave screenshots won't ley ne upload them right n9w
 
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BlueCollarTahoe

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all screenshots were done at 2kRPM after reaching operating temperature with nothing extra on and lights off.

View attachment 198512 View attachment 198513 View attachment 198514 View attachment 198515 View attachment 198516

Screenshot_2018-05-04-14-42-29.png Screenshot_2018-05-04-14-42-44.png Screenshot_2018-05-04-14-45-18.png Screenshot_2018-05-04-14-45-31.png Screenshot_2018-05-04-14-45-56.png
 
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BlueCollarTahoe

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It's your cats. Those lower O2 sensors should be moving around like the upper ones.

really? i thought the b2s2 was normal? ive only changed the up and down on B1 about 15k miles back acdelco. test the cats next??
 
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BlueCollarTahoe

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MagnaFlow 93419 Direct Fit Catalytic Converter

thoughts on this replacement kit if it is indeed the cats?
 

swathdiver

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You're right, my mistake in that the lines from both the upstream and downstream look similar only while cold, not hot. Your bank 1 is more normal than bank 2 lower sensor, they should both respond to rpm changes.

Is the 93419 the whole enchilada, cats and y-pipe? I installed basically the same thing on mine in February, 51578 for GMT900, and it's working great and my mileage came back after a couple hundred miles as the cats wore in.
 
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BlueCollarTahoe

BlueCollarTahoe

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You're right, my mistake in that the lines from both the upstream and downstream look similar only while cold, not hot. Your bank 1 is more normal than bank 2 lower sensor, they should both respond to rpm changes.

Is the 93419 the whole enchilada, cats and y-pipe? I installed basically the same thing on mine in February, 51578 for GMT900, and it's working great and my mileage came back after a couple hundred miles as the cats wore in.


not sure i just looked at the best rated ones real quick. looking at that video rhe S2 jumping is actually the one thts off? but off in a wat showing cat damage or o2 sensor damage?
 

Scottydoggs

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MagnaFlow 93419 Direct Fit Catalytic Converter

thoughts on this replacement kit if it is indeed the cats?

hes in NY. if the cats are bad hes needs a CARB compliant cat to pass inspection, just like that ****** state CA.
 

swathdiver

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not sure i just looked at the best rated ones real quick. looking at that video rhe S2 jumping is actually the one thts off? but off in a wat showing cat damage or o2 sensor damage?

The cat. If you want to double check the O2 sensor performance, swap sides and run another scan.

My right side cat had been changed out. Couldn't have been in there long as there was little salt corrosion. It failed before the original on the left and that resonator at the end of the Y had honeycomb material that the scrap yard paid me for too. Not sure if yours will have that. The point is, unless you're really tight on funds, change them both or all three. The Magnaflow Y is nicely designed and that alone should help flow.
 
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BlueCollarTahoe

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Going to laser tell check the cats
Will update then go from there i guess. I just hate throwing parts at something when ots expensive i rather know which direction for sure to head to.
 
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BlueCollarTahoe

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Update:

Got an unfrared thermometer laser. Whats the optimal condition to get the best reading? After putting it Under 2k rpm? After highway Driving? Idle at operating temp?
 
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BlueCollarTahoe

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Here are some readings sitting idle in park after highway driving for 15 minutes and the car is at operating temperature. This is about an inch above the cat and an inch after the cat wit the laser temp:


Driver side:

Before: 329
After: 345


Passenger side:
Before: 340
After: 358

Dobt know how accurste the reader is I tried to tske it in the same spots same distance away. What next? This is all F degrees.
 

Scottydoggs

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id get it on the hwy and rip into it for a bit, then pull over and check em.

one cats much closer to the exhaust manifold right? could be why its a bit warmer.
 
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BlueCollarTahoe

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I believe th3 driver side one is the closer one. The pipe cuts across to the right side of the trick where the other one is. A lot of metal around it that's warm maybe why its hotter. Yea i got the one from harbor freight new batteries in it. What ya think i should do next?
 

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