Running rough periodically for a couple years, became worse. Loss of power at high speeds. Diag code 118, low power on secondary? Switched both coil packs with some cheap knock offs. Then, engine was running worse. Code 172...changed O2 sensor. Seems to run smoother but still shows code 172, knocks when cold like a banging right on the floor or firewall. I’m thinking maybe the Catalytic converter or vacuum system? Seems to be breathing poorly in all gears. I did run out of gas a couple months back, did not change the filter yet. Also, have not checked the s-plugs. Any ideas? Thank You

 

1993 Ranger 2.3L ?

 

I would suggest compression test. Should be within 5-10 percent difference between psi readings. Usually anything below 140 psi is not good. I had to get this deluxe compression tester because it has an extended reach hose. My ford ranger plugs are real deep in there and the normal/regular compression tester can't reach down to the threads. Mileage helps. For vacuum leaks a paint can smoke tester off ebay is like $60. I would do compression first though by the sounds of it; Also doesn't P0118 means coolant sensor not coil pack? I could see leaking valves causing code 172 allowing more gasoline into the exhaust. Older rangers are known for leaking exhaust valves due to the valve seat.

https://www.harborfreight.com/deluxe...-pc-64917.html

 

Yes, engine is 2.3 L.

sorry, the original code was 218. “No spark from secondary coil pack”. After replacing, the engine did run smoother at first, then something new. The O2. I read a fuel pressure article, maybe caused by plugged fuel filter from running out of gas? Check light still comes on, but doesn’t stay on.

 

All code 172 really means is too much gas too little oxygen. Could be a million things. How many miles does the car have? If its 200,000+ and expecially 250,000 i would compression test because that's when those engines are known to loose compression and die. 250k specifically google it. Now tacomas are like 400k its all about how the engine is built. IE how much the car costs. Knocking is a tell tale sign of loss of compression. Wouldn't even waste my money doing anything else with a car that sounds like that. Its real easy all you do is pull 4 spark plugs and stick a hose in then crank the engine maybe 30 mins. You could even probably rent the compression tester for free from an auto parts store. Remember what i said about the deep reach hose though if it isnt screwing into spark plug holes. Timing could cause this also but compression test is way easier to do. Valve job ain't hard on a 4 cylinder if it is compression.

 

Ok, sorry for the long delay in response. Changed the fuel filter, o2 sensor, plugs, wires, 1 cheap coil cracked so switched back to original. Runs stronger now. Thought EGR could be the problem with the popping and banging, but that has cleared up for now. Still getting major loss of power when under a load or on the freeway. Code 217 primary circuit failure in coil 3? Multimeter test shows nothing, ICM was taken out but auto parts store couldn’t test it. Any suggestions with this diagnosis code?