My 93 ranger 2.3 is running like hammered dog sh!&, it was running perfectly then going down the road about 50 MPH it seemed like someone hit a switch and it just started puttering, loss of power, drinking gas,exhaust pinging when accelerating ,there is no CEL on. According to my snap on scanner there is only one code and it’s 172.I replaced the 02 sensor,I’ve sprayed every vacuum hose, intake,injectors with brake cleaner several times appears not to be a vacuum leak either. I swapped out the EGR and the pressure solenoid (used), spark plugs,1 coil and ICM are new. The MAF is working properly according to my scanner I have 17 in/hg of vacuum being supplied to the EGR vacuum solenoid however there seems to be no vacuum output to the EGR. The solenoid has 14v going into it. The EGR position sensor has a voltage reading of .5 on one prong of the connector, the other 3 prongs on the connector show no voltage.when I sprayed cleaner all around the EGR the rpms didn’t pick up so I assume it’s not leaking. I am not sure if the EGR and emission components are working properly I am at a loss,I drive this truck a 1000 miles a week and absolutely need it dependable. The engine itself is solid nice tan color on the spark plugs so any ideas or testing procedures would be appreciated.

 

EDIT: WOOOPS, its a OBD-1 - 172 Lean Code. SO Lets think about this some more. Seeing as how this is a 93 & the code is for Too much O2 in the exhaust at the O2 sensor, it happened suddenly at highway speed, so the red brick should be showing corrupt fuel trim readings.

Focus on what could corrupt fuel trim Lean, on this year/model fuel delivery system & would cause wimpy power out. A good suspect might be a faulty fuel pressure regulator, or maybe the vacuum line to it. On this year model the FPR is mounted under hood on the fuel rail. You might inspect its vacuum line condition & fitting on the FPR vacuum connection, it needs to be tight fitting, no soft mushy swelled up rubber, nor hard baked out cracked/split condition.
Or hook up your fuel pressure gauge at the fuel rail Schrader valve test port & post the measured fuel pressure Numbers & fuel delivery rate, which should be something like 1/2pt - 15 seconds pump run time.

If all that checks out ok, have a listen on each fuel injector with a stethoscope, or fashion one from a long wooden dowel, long piece of tubing, or long screwdriver, one end on the injector, the other to your ear & listen for a difference in injector clicking. They all should sound the same.
If you find a suspect, pull that cylinders plug/s & see if the deposits indicate it's been running lean. If so, remove the suspect injector & measure it's resistance. All injectors should measure within specified range & their resistance should Closely match. If injector resistance is ok, check it's internal sintered filter to see if its clogged with deposits, such that it's giving a lean squirt.

Some thoughts for consideration, let us know what you find.

 

Thanks for the info. My red brick has the SFTRIM at 0 and the LFTRIM at 10 (or vice versa not near the scanner to look it up) these values are constant and have not changed at idle or manually throttled. What I have found upon spraying brake cleaner into the backside of the EGR the engine rpms increase also when running I manually put vacuum to it when I increased vacuum up to 15hg/in. The engine stumbled and ran rough as it should however it would not hold vacuum.I believe the EGR is bad for one thing.secondly I tested the EGR vacuum solenoid,I applied 12 v and a ground jumper to its male spade connectors and I did not hear it actuate.thats making the assumption that since it acts as an solenoid there should be a distinct click when it’s powered up.
I have listened to the injectors and not heard anything unusual, I’ve pulled the vacuum line off the fuel diaphragm and nothing happened.is that unusual? I haven’t checked the fuel shrader valve (didn’t really notice one on the fuel rail) what is the psi running 35-50? The spark plugs are three weeks old, Thats not to say they couldn’t be fouled but it sure is a pain in the butt to get at the ones under the intake😀 the engine is pinging on acceleration,fuel consumption is double, nox exhaust and rough idle ,I believe it’s pointing towards an emissions problem but I have been wrong before, therefore I will look at everything you have mentioned.the live data from the scanner KOER, seems good however I am curious why the TRIM data is constant I haven’t educated myself on TRIM.

 

Problem solved replaced the EGR and vacuum solenoid.

 

Ok good find, fix, feedback & to hear all now seems well. The EGR valve is rather robust & doesn't usually cause problems unless it's rusty & falling apart, or clogged up with carbon from an oil burning engine. Its vacuum control solenoid, or vacuum lines are usually the culprits. Interesting that the Red Brick wasn't seeing any fuel trim, or EGR system corruption, or that the vehicle ECM wasn't detecting anything wrong with fuel trim, or with the EGR system, although your sniff testing did indicate some components belonged on the suspect list, so good trouble shooting with the propane sniffer.

 

Mine 1997 460 efi is doing th same and I get code 212 and 172.