Someone stole gas from me and now my engine runs weird?

[Dustin Jackson]

@Just Fishing I don't have one but I can see if I can borrow one, what exactly would I be looking at/for if I got my hands on one?

 

[Doubeleive]

unless they disconnected the filler tube there is no way they got gas out of the tank without drilling a hole in it. I also think if anything was put in the tank you would have seen evidence of it around the filler. I assume you found nothing and that it was clean. In this case I think it is possible your mind is playing tricks on you.
i would perform some simple basic maintenance.
get a new air filter
get a can of maf cleaner $3-4.00 dollars
get a can of throttle body cleaner $3-4.00 dollars
get some soft rags (lint free)
get a bottle of injector cleaner the lucas big bottle is your best buy (add 10 oz per tank full of gas) the lucas big bottle will do 3 tank fulls
replace the air filter
remove the intake housing and maf
spray the maf off real good both sides and set it aside and let it dry. (do not touch any parts of the maf with anything other than with spray from the can)
using the rag spray the rag and throttle body butterfly and clean it real good, you can push the butterfly open with your finger just hold it open with a finger gently while cleaning the surface inside and out do not force it open beyond where it stops. you will see black carbon residue that is normal and is what you need to clean off.

then re-install the intake and maf, make sure the intake is on correctly and bolts are snug.

drive it, you may notice some idle fluctuation at first start after cleaning but it will clear right up.

other than that if the plugs and wires have 100k or more it is time to replace them and all 4 02 sensors

 

[Dustin Jackson]

@Doubeleive I think you're right man. Paranoia and OCD getting the best of me.

 

[Dustin Jackson]

@Doubeleive What is the average life of the cats on these things? I am about 190,000 and think they are original

 

[Doubeleive]

@Doubeleive What is the average life of the cats on these things? I am about 190,000 and think they are original

cat's should last for the life of the vehicle unless you drive like me in which case you would end up with a check engine code for cat inefficiency or you would start to see a noticeable drop in mpg and then get a code eventually. 02 sensors are rated for 100k but should/could last longer also can be dependent on how you drive I suppose. If you replace them it is recommended to do all 4 at the same time. a set of 4 oem runs close to $200 and you need a 02 socket unless you want to fight getting them installed.

 

[Just Fishing]

cats can become plugged, and your tahoe would run like shit if that was the case.
You can check flow by removing the sensor one and sensor 2 to see if there is a flow difference.
there is also a cat further back, it's all part of the same gigantic Y

 

[Just Fishing]

@Just Fishing I don't have one but I can see if I can borrow one, what exactly would I be looking at/for if I got my hands on one?

I would go into fuel system data.
You should see things like fuel pressure commanded, and actual.
they should be close.

Other things in there also, but it has been a while since i fkd around in the fuel system info stuff.

 

[Fless]

Do what @Doubeleive suggested. If something's really wrong with it, I'd say get someone to diagnose it instead of guessing 'could it be this' or 'could it be that.'

 

[gooffeyguy]

unless they disconnected the filler tube there is no way they got gas out of the tank without drilling a hole in it. I also think if anything was put in the tank you would have seen evidence of it around the filler. I assume you found nothing and that it was clean. In this case I think it is possible your mind is playing tricks on you.
i would perform some simple basic maintenance.
get a new air filter
get a can of maf cleaner $3-4.00 dollars
get a can of throttle body cleaner $3-4.00 dollars
get some soft rags (lint free)
get a bottle of injector cleaner the lucas big bottle is your best buy (add 10 oz per tank full of gas) the lucas big bottle will do 3 tank fulls
replace the air filter
remove the intake housing and maf
spray the maf off real good both sides and set it aside and let it dry. (do not touch any parts of the maf with anything other than with spray from the can)
using the rag spray the rag and throttle body butterfly and clean it real good, you can push the butterfly open with your finger just hold it open with a finger gently while cleaning the surface inside and out do not force it open beyond where it stops. you will see black carbon residue that is normal and is what you need to clean off.

then re-install the intake and maf, make sure the intake is on correctly and bolts are snug.

drive it, you may notice some idle fluctuation at first start after cleaning but it will clear right up.

other than that if the plugs and wires have 100k or more it is time to replace them and all 4 02 sensors

Do the tank fill pipes on the 900s have something the 800s don't? I've siphoned gas from my 01 before replacing the fuel pump.

 

[Doubeleive]

Do the tank fill pipes on the 900s have something the 800s don't? I've siphoned gas from my 01 before replacing the fuel pump.

I believe there is something in there, some kind of restrictor, you might be able to fit a very small tube in