I have a 93 F-150 5.0L (302) that is sluggish on acceleration. When the truck is cold it runs like a champ as soon as it warms up it wants to spit and sputter making a wear popping sound on front driver's side when trying to accelerate. Could an O2 sensor cause this?

Thanks for your time!

 

Popping noise could be cracked exhaust manifold. That would make for an exhaust leak upstream before the O2 sensor and thus would give the PCM erroneous Air/Fuel ratio and lead to driveability problems. Could also be loose exhaust manifold bolt.

Either way, is the CEL on? And do you have a code reader? If no code reader available, you can use a paperclip to check for stored codes. The Check Engine Light doesnt need to be on for problems to be present.

 

Yea bad O2 or just time for a tune up

 

The Check Engine Light is not on. Just changed the spark plugs & wires, Distributor & Rotor. Wasn't sure if it had to do with the EGR Valve or EGR Vacuum Sensor. Without the CEL on I don't think any codes will pull up.

 

Common myth with these vintage trucks. This is the #1, most common mistake.
Check out this link, you'll be really surprised with all the information that is here and how to pull codes on these vintage trucks for free.

Www.fordfuelinjection.com
Also, now you threw a curve ball when you said "EGR valve or EGR Vacuum solenoid". Can you help elaborate?

Also, I forgot to mention, when cold, the PCM isn't taking any info from sensors like the O2, or ECT, IAT, but preset parameters for startup and open loop. Just about till 180 F. Then the PCM goes into closed loop and if any if those sensors are failing or have failed, then you get a crappy running engine.

 

It is just a guess on the EGR system. I know it has to do something involving air/fuel mix seeing its only when it warms up.

 

Right! That's how I figured it work with them PCM. Just sick of nickel n diming me and changing all this stuff that doesn't need to be messed with. When I got the truck a couple weeks ago it had no exhaust after the Cat. It seemed to run ok even when warm but would shift hard. I put a Flowmaster 40 series on it dumped before axle and now its running horrible. Yet the trans is shifting fine now.

 

fuel pressure drops to 18/20lbs when you acc.