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OK Im a newbe here,so go easy

 

I have a 99 chevy Blazer 4 door with no mods done at all straight up stock.Its a 4.3L v6 auto.

 

Ill try to explain as best as I can.

 

This truck as no power what so ever.when i start it and then put it in drive and hit the gas it falls flat on its face,back fires out the carb,and has some sorry gas milage.even after it get warms up no power,if im going like 50 and hit the gas to try and pass someone it just about dies.The truck as 49,875 miles on it.The only thing i have done to it is change the fuel filter and that didnt change a thing.I have tried a few other message boards and no one can seem to help me.This is the only board that seems to know what there doing so I hope you can help me.Please ask me anyquestions you need to help.

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OK Im a newbe here,so go easy

 

I have a 99 chevy Blazer 4 door with no mods done at all straight up stock.Its a 4.3L v6 auto.

 

Ill try to explain as best as I can.

 

This truck as no power what so ever.when i start it and then put it in drive and hit the gas it falls flat on its face,back fires out the carb,and has some sorry gas milage.even after it get warms up no power,if im going like 50 and hit the gas to try and pass someone it just about dies.The truck as 49,875 miles on it.The only thing i have done to it is change the fuel filter and that didnt change a thing.I have tried a few other message boards and no one can seem to help me.This is the only board that seems to know what there doing so I hope you can help me.Please ask me anyquestions you need to help.

 

 

 

 

With code p0101 for a mass air flow sensor and a p0171 O2 sensor Fuel Trim System Lean Bank 1

 

Top 3 things that it could be

mass air flow sensor

intake manifold gasket leak

crankshft posion sensor

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  • 3 weeks later...

remove the maf and clean the wire with some brake clean and and scrape the dirt balls off of the wire with a tiny screw driver

be carefull not to damage it

 

 

 

 

OK Im a newbe here,so go easy

 

I have a 99 chevy Blazer 4 door with no mods done at all straight up stock.Its a 4.3L v6 auto.

 

Ill try to explain as best as I can.

 

This truck as no power what so ever.when i start it and then put it in drive and hit the gas it falls flat on its face,back fires out the carb,and has some sorry gas milage.even after it get warms up no power,if im going like 50 and hit the gas to try and pass someone it just about dies.The truck as 49,875 miles on it.The only thing i have done to it is change the fuel filter and that didnt change a thing.I have tried a few other message boards and no one can seem to help me.This is the only board that seems to know what there doing so I hope you can help me.Please ask me anyquestions you need to help.

 

 

 

 

With code p0101 for a mass air flow sensor and a p0171 O2 sensor Fuel Trim System Lean Bank 1

 

Top 3 things that it could be

mass air flow sensor

intake manifold gasket leak

crankshft posion sensor

 

 

 

 

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A clogged cat wont make a vehicle fall flat on its face, it will take off and then start slowing down on accel the high the rpms get. the mass air flow sensor will cause it to run ruff, idle poor, sputter on accle or fall on its face...

second you would not get a p0101 or p0171 codes you would normally get a p0420 (bank 1 catalyst low efficiency) or p0430 (catalyst low efficiency for bank 2) and some times one or more of these codes will show p0138, p0139, p0140, p0158, p0160, p1147,p1167

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ok this is what I have done

 

I did a tune up seeing that the cap and rotor didnt look to good.

changed car,rotor,plugs and wires and cleared the computer of any codes(p0101 and p0171).That seemed to have done a little performance help but did not fix the problem because it is still there.After a few days of driving about 25 miles or so (i drive about 8 miles a day to and from work).The SES light came on only showing the code P0101.I have looked at the Mass Air Flow senser and does not look dirty at all.air filter is clean.The truch is also back firing out the carb.I have searched on line about this issue and came up with after a few times of back fireing the back pressure will fracture the MAS.

 

Does any one know how to check it with ohm meter ect to definetly find out if its bad.I really dont want to start replacing parts and finding out that was not it.I know the MAS is pricey but not 100% sure.

 

Thanks for all the help.

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you would normally get a p0420 (bank 1 catalyst low efficiency) or p0430 (catalyst low efficiency for bank 2)

Not trying to differ but these codes have nothing to do with a cat being clogged. They set when the post cat O2's vary at to fast of a rate which indicates that the converters are not doing their job. A back pressure test is easy and I think it should be done next. A clogged cat will set a MAF code, been there and have the t-shirt. :-)

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  • 4 weeks later...
ok this is what I have done

 

I did a tune up seeing that the cap and rotor didnt look to good.

changed car,rotor,plugs and wires and cleared the computer of any codes(p0101 and p0171).That seemed to have done a little performance help but did not fix the problem because it is still there.After a few days of driving about 25 miles or so (i drive about 8 miles a day to and from work).The SES light came on only showing the code P0101.I have looked at the Mass Air Flow senser and does not look dirty at all.air filter is clean.The truch is also back firing out the carb.I have searched on line about this issue and came up with after a few times of back fireing the back pressure will fracture the MAS.

 

Does any one know how to check it with ohm meter ect to definetly find out if its bad.I really dont want to start replacing parts and finding out that was not it.I know the MAS is pricey but not 100% sure.

 

Thanks for all the help.

 

 

 

 

i just went through this with an 01 jimmy 4.3L. w code 2wd. with 88K mi's.after upgrading to K&N filter, mine started throwing p0101,p0102,p0171. pulled my hair out for a week. called the tech support at k&n and they enlightened me that new or freshly cleaned k&n filters can leave oil droplets on the wires and cause MAF malfunction. my symptoms were exactly like you describe, bad performance, backfire, pop,snort,etc. cleaned the maf WITHOUT touching the tiny wires, with choke/injector spray, then blew it gently with the air in a can you blow dust out of you keyboard and it ran better, but not normal. recleaned the filter, helped, but still not as before. ended up putting in a MAF from a t-boned jimmy at u-pick wrecking yard, and no troubles since. :flag::bs:

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