DTC p1400

No I did not. I was under the impression that there were two different PTFE sensors and one had to have replacement hoses and one did not. And thinking I had the one that didn’t require new hoses, I didn’t replace them. So I guess I should try to find replacement hose for this? And will I need another new PTFE sensor? Or will this fairly new one still be usable?

Yes, replace hoses. They are special hoses and different sizes.

Roy

Okay. Thanks. I will pursue new hoses.

You are welcome.

Roy

Okay so I’ve replaced both hoses on the DPFE sensor. After starting engine, check engine light illuminates. I turn off the engine and extract 3 TDC codes: P0102- Mass Air Flow sensor circuit low, P0113- Intake Air Temp. sensor, and P0191- Fuel Rail Pressure sensor. From what angle should I tackle these codes?

Oh I also replaced the DPFE sensor with a new one.

A picture of the old DPFE sensor and the hoses with the sensor tips broken off in the ends of the hoses.

Okay,

191

P0191
Descriptor
Fuel Rail Pressure Sensor Circuit Performance (Frp)
Probable Causes
Circuit Resistance Excessive
Fuel Rail Pressure (FRP) Sensor Damaged
High Fuel Pressure
Low Fuel Pressure
Low or No Fuel

102

P0102
Descriptor
Mass Air Flow (Maf) Circuit Low Input
Probable Causes
Closed Throttle Indication In Throttle Position Sensor (TPS) System
Intake Air Leak Near Mass Air Flow (MAF) Sensor
Mass Air Flow (MAF) Circuit Open to Powertrain Control Module (PCM)
Mass Air Flow (MAF) Circuit Shorted to Ground
Mass Air Flow (MAF) Return Circuit Open to Powertrain Control Module (PCM)
Mass Air Flow (MAF) Sensor Damaged
Mass Air Flow (MAF) Sensor Disconnected
Power or Ground Open to Mass Air Flow (MAF) Sensor
Powertrain Control Module (PCM) Damaged
Voltage Power Open to Mass Air Flow (MAF) Sensor

113

P0113
Descriptor
Intake Air Temperature (Iat) Circuit High Input
Probable Causes
Harness Open Circuit
Improper Harness Connection
Powertrain Control Module (PCM) Damaged
Sensor Damaged
Sensor Signal Short to Power

Okay so scratch that last message about the 3 DTC codes. I found that the Mass Air Flow sensor was unplugged for some reason. So I plugged it back up, erased the DTC codes from memory. Started the car and drove it less than a mile and it’s doing the same thing as before. Complete loss of power transmission very, very hard shifting. Didn’t think it would make it back up the hill I live on, but surprisingly it did. The hoses haven’t blew off the DPFE sensor but it acts just like they have. Don’t know where to go from here.

If you disconnect the mass airflow, does the power come back?

Roy

It seemed like some of the power came back. But not all of it. And very erratic shifting of the transmission.

Is it more of the transmission than the engine.

Roy

It seems like it is now. But always before it has seemed like the engine.

Does the transmission shift at normal shift points and go through all the gears?

Roy

Doesn’t shift right. Shifts erratically at the wrong time. Can’t drive it enough to see if it does it through more than first or second gear. Not enough power to get it going that fast.

Have any new codes appeared for the transmission? They will be 700 codes.

Roy

No. No new codes. Surprisingly the check engine light did not come on. Although I only drove a short distance.

I am concerned the engine is revving correctly but the transmission is not shifting to allow speed to build.

How long since you change the fluid and filter in the transmission?

Roy

Never. Since I bought the car used. I really don’t think it is the transmission. It was shifting fine before all this with the DPFE sensor. And wasn’t really shifting that bad with the bad DOFE sensor. Just was taking too long to shift. But now the shifting is up then down the up again. With the mass air flow unplugged that is.

I would not dismiss it that easily.

Can you monitor the voltage of the mass airflow at idle and at 1500 RPM?

Can you give me the long term trims on the upstream O2 sensors?

Roy

No my scan tool is a simple one. It doesn’t have two way data. Just DTC codes.

Can you get one to read live data?

Roy

I’m not sure. I can check about one. May take me a few days.

Okay, keep me updated.

Okay. Will do.

Thanks.

Roy

Thank you.

When you get the tool, give me the long term trim percentage readings at idle and at 1200 RPM.

Roy

Well, I can’t seem to locate a scan tool with live data at this time.

I can push the gas to the floor and it will only rev to about 3,000 rpm's.

Did you replace the cat converters?

Roy

Yes. The two front ones. The y pipe. Exhaust is strong coming out of muffler. There doesn’t seem to be any blockage through the exhaust.

Okay, that is determined by doing a back-pressure test. You insert a back pressure gauge in place of the upstream O2 sensor. Anything over 1.5 lbs at 1500 RPM is no good.

Also, check the fuel pressure. Low fuel pressure will limit fuel.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Roy

I don’t have a back pressure gauge. Is it possible the hoses connecting the DPFE sensor are switched? Something I read said that the hoses don’t line up straight with the ports they connect to. That the hoses cross before connecting to the sensor. I didn’t know if this was true or not? Being different size hoses, I thought they would only connect to the correct size ports for each respective hose.

No, to the hoses.

You can rent one or buy one for the testing.

The backpressure gauge is not expensive at all.

Roy

Okay. I’ll look into getting one.

Keep me updated.

Roy