Losing power, won't accelerate.

[superhampster]

I have a 98 Sierra with a 4.3 v6. It's learned a new trick lately. It will start up and run fine for a little bit but then it will start to lose power and will not accelerate when I push down on the gas. Eventually it will get to where it can't climb a hill or reach the speed limit. If I pull over, cut the engine for a minute and start it back up it will run fine for a little while longer, but eventually it will go back to losing power. This weekend I changed out the fuel filter. It really needed it. This didn't solve the issue however. I was thinking either I have some junk in my gas tank or maybe exhaust restriction. Any ideas? thanks!

 

[98trck]

will the engine rev up when parked
if it won't rev the cat may be clogged if that is the case disconnect the exhaust at the exhaust manifolds then will the engine rev if so the cat is clogged

 

[irishfogarty]

try changing the fuel filter. I just had it happen to mine where i would leave my driveway, and when i went to accelerate it just dogged down. Its either the cat or fuel filter would be my bet. start with fuel filter since their cheap

 

[irishfogarty]

my bad didnt read that you changed the filter.get your cat tested

 

[superhampster]

These are my engine codes.

Code Type Status Description
---- ---- ------ -----------
P0108 PowerTrain Stored Manifold Absolute Pressure/Barometric Pressure Circuit High Input
P0131 PowerTrain Stored O2 Sensor Circuit Low Voltage
P0151 PowerTrain Stored O2 Sensor Circuit Low Voltage
P0420 PowerTrain Stored Catalyst System Efficiency Below Threshold
P1870 PowerTrain Stored Manufacturer Defined
P0151 PowerTrain Pending O2 Sensor Circuit Low Voltage
P0420 PowerTrain Pending Catalyst System Efficiency Below Threshold

P1870 is an issue with my transmission that I'm aware of.

 

[superhampster]

We put on a new map sensor and cleared the codes. It didn't help, but the trouble codes haven't come back yet.

 

[catliftresearch]

Catalytic converter plugged

Yup, all the symptoms of a clogged catalytic converter.

 

[Ackbobby]

Did u try some good ok fashioned mystery oil and see bout running it for a
Tank full or so also injectors? And well as maybe map sensor not enough air going in n suffocating it check air filter as well? Fuel lines throttle body as well