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Having some weird issues with my Chevy pick up

Hello guys,

I am working on some problems with my truck and I am kind of stuck, so I was hoping I could get some advice. Everything started with error codes P0141 Oxygen Sensor Heater circuit bank 1, and sensor 2 P0155 Oxygen sensor heater circuit bank 2 sensor 1. I replaced both Oxygen sensors, now I have the error code P0141 back and error code P1441 Evaporative Emission Control System Continous Open Purge Flow. After researching this error code I decided to replace the [Vapor Canister Purge Valve, which will arrive next Tuesday. When I first drive the truck, when I am in second gear at about 1800rpm the truck will start shaking, like there is no power, and I am forced to go into 3rd, and the moment the truck reaches 30 MPH it will start shaking again, and I have no choice but to shift to 4th. The problem is if this is a hill because the truck is having a hard time going up a hill on 4th at 35 MPH. (is this because of the error code P1441 Evaporative Emission Control System Continous Open Purge Flow.?

The catalytic converter is about 6 months old, the muffler is old, but to me, it does not seem loud. I now have a scanner for live streaming, but I am not sure what should I check that could help me solve the truck problems (perhaps you guys could suggest what I should be live streaming for and I will report it back here.

My tag expires soon so I am kind of on the spot to fix these problems, so your suggestions are greatly appreciated,

Happy Thanksgiving,

Steven

Jordan, It would be useful to have the year of the pickup, the engine it has, the transmission type and how many miles are on it.

My Chevy truck has had O2 sensor heaters fail in 3 of the 4 O2 sensors. it has 138K on it now.

If P0141 has re-appeared, is it possible you replaced the wrong sensor? Or the new one has failed? Or you damaged the wiring when you changed it or even knocked a pin loose in the connector? I’d check wiring first.

P1441 Possible Causes - notice it doesn’t include a purge valve

  • Missing or loose fuel cap
  • Incorrect fuel filler cap used
  • Fuel filler cap remains open or fails to close
  • Foreign matter caught in fuel filler cap
  • EVAP canister or fuel tank leaks
  • EVAP system hose leaking
  • Fuel tank leaking

It is possible there is a connection with how poorly the truck runs. Have you checked fuel pressure and the condition of the fuel pump and lines? Fuel lines rust out on these trucks as they get old and pumps don’t last forever. Mine actually rusted out the outlet and inlet pipes and caused a small leak. If you put in a new pump, change the tank pressure sensor that mounts into the pump at the same time.

Hey Mustangman,

You are so right! It is a 1996 V6, manual 4.3L about 65,000 engines, the truck is 130,000. I was very careful with the wiring when I replaced the sensors. I think there is a gas leak on the neck of the gas tank because when I filled it up a little bit of gas spills… Is that like a rubber hose that should be tightened with a clam?

Is there a way to post a picture here?

Could be a clamp, might be rusted pipes. Can’t tell from the internet.

This thing needed a new engine at 65k? The 4.3 is like a cockroach. Darn near un-kill-able. Rust is an issue on trucks far newer than this one. If it spent it life in the desert instead of the rust belt, assume every rubber line needs replacing.

Gasoline lines were replaced 6 months ago! engine is new because It sat one winter and I did not realize it did not have enough antifreeze and the engine cracked. regarding the P0141 error, is there something I can live stream with the scanner to help me determine what the problem is?

Nothing to live stream on a P0141… it is a bad heater. That won’t show on live data. The O2 sensor will just warm up slower than the other bank. You might be able to see that but I doubt it on a downstream sensor.

Is there a way to check if the EVAP canister is faulty? Any idea of what could be making the truck shake like there is no power when I am in second gear at about 1800rpm? forcing me to go into 3rd, and the moment the truck reaches 30 MPH it will start shaking again, and I have no choice but to shift to 4th. This is true on a straight run is way worse if it is up the hill.

On live stream watch the MAP value when accelerating. MAP. i.e. vacuum, will drastically drop if there is a restriction in the exhaust or starving for fuel. The bucking under acceleration is indicative of losing fuel pressure. I found that the short rubber hose connecting the fuel pump to the metal line was split on a Chevrolet pickup with your problem

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Thank you Rod_Knox,

I am not finding a MAP option on my scanner, I found
“Evap. System Vapor Pressure” PID:01 33
Absolute Evap System Vapor Pressure, PID: 01 54,
Evap System Vapor Pressure PID01 54
or Fuel Rail Pressure (absolute) PID: 01 59

Is it one of these and if not, could you please specify the entry I should be looking for?

Also, That hose connection the fuel pump to the metal is outside the gas tank… correct?

Thank you so much for your help!

Watch that one if it is actually giving you fuel pressure. Some scanners show the input but if your truck does not have a pressure sensor, it won’t read. Steady pressure is important. If it drops when you accelerate, there is a pump problem.

Manifold absolute pressure (not MAP) may be the label your scanner uses OR vacuum or “manifold pressure.”

Correct