Check engine causing bad gas milage

[94SHOusmc]

Before I go get my codes read I thought I might see if any of you have had this problem. For a few months now any time I get on the gas my check engine light will come on for a brief period of tome (5-6 min) Then go off. Non e of my guages read bad and it would go off if I turned off the car so I just put it off as being a bad sensor and I would get it looked at later. (yes I know that is prabably bad and if you ever see me you can slap my wrist for it) For christmas I made the drive form where I am stationed in VA to my home town in GA. And I notieved that I was getting terrible gas milage. Normally I get roughly 100 miles to the quarter tank. This time I was only getting around 75. I chalk it up to the check engine light and whatever sensor is going/gone bad. What sensor would cause this? And another thing. At speeds of 85-90, what are your revs suposed to be roughly. It seemed like I was reving a little higher than usual, hence the bad gas milage. For those that need to know, it is a 1994 ATX with 152,000 miles. 60k done again at like 120,000, and I got an oil change the day I made the trip. I am heading back to VA on the 28th so any help is greatly appreciated. I am limited on tools here since all my stuff is back home, so I do not have a multimeter to check the codes with. Which is why I might have to sacrifice money to get them checked. Thenks for taking the time to read all this jibber jabber.

 

[ckinart]

94SHOusmc:
I am limited on tools here since all my stuff is back home, so I do not have a multimeter to check the codes with. Which is why I might have to sacrifice money to get them checked.

You don't need to spend any money to check your codes. Have a look here for instructions on how to check your codes with a short piece of wire or even a paper clip. Check them out and let us know what comes up. thumb

 

[NotSoSlowSHO]

Codes:

autozone checks them for free.

So can you, with only a paperclip wink

try a search.

 

[94SHOusmc]

111 - System checks OK

167 - 167 No Throttle Position sensor change in "goose" test (must get at least 25% rotation)

172 - Oxygen sensor not switching - system is or was lean - Single Right or Rear HO2S

225 - Knock sensor not tested (ignore if not pinging)

Only prob I see is 172. Make sense to anyone? I can replace that. I just need to know which sensor. Anything else? I did the cylinder test and everything is ok there.

 

[NetNinja]

same thing happened to me.
Replaced both Oxygen sensors and all is well now.

 

[94SHOusmc]

Took off both sensors and did the flame test that shotimes.com shows you how to do and both failed. I will try to replace both of them. I have heard ONLY to use FORD OEM sensors, but they cost like 150 bucks EACH. Will after market ones (Bosh...) work well? They are only aabout 60 each and are at autozone. If not those I need some that are deendable and Ones I can get by tomm morning since everyone will close for christmas, and I have to drive my car to Atlanta christmas morning. So this has to be done by Tommorow after noon.

 

[Rob94]

The Bosch sensors are fine. Whoever told you to use only Ford OEM sensors are either FoMoCo stockholders, or are ignorant.

 

[wood_e]

I got some borg warner sensors, they work well too...

BTW have fun with the rear O2 sensor. Thats a REAL B*TCH if you don't have the right tools. A u joint an extension, and the special O2 socket made that job much easier....

<small>[ December 23, 2003, 09:43 PM: Message edited by: wood_e ]</small>

 

[AutoSHO]

Yes, the rear Oxygen Sensor on an ATX is "interesting" to change. Just don't get frustrated. We did it from the top, I think that is the easiest way.

Thats one thing thats much easier on the MTX.

 

[sdpatt]

I agree with the 172 being the only relevant code and yes, that rear O2 sensor is a tough one on the 3.2L SHO. I access the electrical connector from above, but the sensor from below with the sensor socket, a U-joint and 9" of extensiones on the socket driver. The Bosch 15716 from AutoZone for $49.00 each should serve you well. Ford doesn't make the sensors - another parts supplier does that. You apparently met someone who works for them. wink

 

[Chris Benvie]

you complained about the revs, is your tranny kicking up when you are on the highway?

Sounds like it might not be going into gear therefore causing it to be revving higher, but it could be something completely different. This happened when my ATX car shit the bed

 

[MilTownSHO]

I was having the same problem, turned out it was an 02 when I ran the codes. I replaced the Y-pipe (one of the cats was dented) with one with 20k on the cats and put new Bosch O2's in. All is well now. Car runs smoother, feels more powerful, and does better on gas mileage thumb

 

[94SHOusmc]

Thanks for all the help guys. Yea the rear one was a pain to try and get out, so I went and bought the special tool, a long a$$ extention, and a swivle. Took like 5 min. The Bosch ones are awsome. I just got home a few hours ago and I saw a HUGE improvement on gas. I replaced both of them and I dont regret using the Bosch ones. Thanks again guys.