Terrible MPG!!

[keenan]

O2 sensors original? May need to look at voltage waveforms with a scan gauge or something to confirm that they are working okay. They will not throw a code unless their about dead.

I believe they are all original.. Are they easy to test?

 

[afpj]

Easy if you have a realtime monitor like scangauge/ultragauge. I use an elm 327 Bluetooth obd2 with torque app and gives me realtime data: precat graph/voltages should cycle rapidly (fast sine wave) and post cats should look almost steady at 0.7v IIRC. some folks on this forum recommend just changing the o2 sensors as part of high mileage maintenance at about 100-120k miles (mainly the precats).

 

[keenan]

Easy if you have a realtime monitor like scangauge/ultragauge. I use an elm 327 Bluetooth obd2 with torque app and gives me realtime data: precat graph/voltages should cycle rapidly (fast sine wave) and post cats should look almost steady at 0.7v IIRC. some folks on this forum recommend just changing the o2 sensors as part of high mileage maintenance at about 100-120k miles (mainly the precats).

Ok. Just ordered the elm 327. Should be here in a couple days and I'll test it then.
Also the fuel I use has 10% ethanol so I'll look around and see how non-ethanol is.

 

[afpj]

warning Will Robinson. Torque app not for iPad iPhone. you should not regret getting the Elm 327 because you have an high mileage car and you will use it more than once

---------- Post added at 11:04 AM ---------- Previous post was at 10:58 AM ----------

Don't forget to clean MAF and TB too

 

[sbubbaklein]

E10, E15, or E85? All give reduced fuel economy.

 

[keenan]

Just did a partial fill up so I could try the non ethanol gas. It was 90 mile trip and I got 10.8 mpg. Not really understanding how I go from 9.3 to 10.8.

 

[keenan]

warning Will Robinson. Torque app not for iPad iPhone. you should not regret getting the Elm 327 because you have an high mileage car and you will use it more than once

---------- Post added at 11:04 AM ---------- Previous post was at 10:58 AM ----------

Don't forget to clean MAF and TB too

So this is the graph I got wit sensor 1 bank 1. Is it good?

 

[afpj]

That looks about right. Bank 2 sensor 1 should look the same. Bank 1 and bank 2, sensor two should nearly look steady-state. If you find that any sensor spends more time near 0 volts, then time to replace. Again, some say to just replace them as A matter of routine maintenance but to me that gets a little expensive.
Btw, Ethanol contains less power (thermal energy) per unit of volume then gasoline, so although e10 or E 85 may burn cleaner, it has less power and therefore you will get less gas mileage with the ethanol blend. In addition to cleaning the mass airflow sensor and throttlebody, consider running some techron fuel injector cleaner for your tank

 

[keenan]

That looks about right. Bank 2 sensor 1 should look the same. Bank 1 and bank 2, sensor two should nearly look steady-state. If you find that any sensor spends more time near 0 volts, then time to replace. Again, some say to just replace them as A matter of routine maintenance but to me that gets a little expensive.
Btw, Ethanol contains less power (thermal energy) per unit of volume then gasoline, so although e10 or E 85 may burn cleaner, it has less power and therefore you will get less gas mileage with the ethanol blend. In addition to cleaning the mass airflow sensor and throttlebody, consider running some techron fuel injector cleaner for your tank

Got the MAF and tb cleaned. That tb was like black in there.. Noticed the rpms jumped from about 520 to 560 so I think that's a good thing. Im going to put the fuel injector cleaner in after my next fill up. Hoping it will help. Thanks for all the info!

 

[Mudfrog]

So I'm using Torque Pro and I'm trying to determine if my O2 sensors are ok. The top of the screen shows the actual readings while the bottom shows a sample graph. If my actual readings do not follow the sample graph does that mean I have issues?

Here is what I'm referring to: