Truck running HORRIBLE after clearing CEL???

So I've had a CEL up for about 3 months. It popped up when my exhaust started leaking. Truck ran fine, just loud. Fixed the exhaust, and just been too busy to clear it. Truck was running great.
Went to the auto part store and cleared it today. Started the truck up and it seemed like it was idling low. Then had decreased power driving the 5 miles home. I'd put the pedal all the way down, and it barely would climb in speed.
Got home, removed battery cable to reset the CPU. Hooked battery back up, start truck, let idle for about ten minutes. Come outside and truck sounds funny. Get in and try to go, and it will barely move. I have it floored in first gear, and it's barely going. Sounds like it's consistently loosing all power. Put it in neutral and same thing. Floor it, and it sputters badly.

Any ideas???

Truck was running completely fine up until clearing the CEL. The code was a P0171 code.

98' Tacoma. 2.7, 5spd.

 

cat? clogged? how many miles on the truck?

 

It would have been in limp mode with your CEL on. That would change how your computer applies power to the motor ect. Your symptoms sound like nasty spark plugs or a flow issue I would check the plugs and wires. Then check the cat to see if its clogged like ^ said just because the plugs will be easier.

 

This. My truck just had the same symptoms. Replaced the plugs, wires, distributor cap and rotor. Also the fuel filter. Runs great now.

 

Take cat off. Start car

 

Something around 150K on the truck.

The exhaust issue has been fixed for some weeks. I've driven the truck over 500 miles of interstate, and 200 of city driving without one issue since. Ran great. 80+mph on interstate.
I just had some extra time today, and figured I'd swing by the auto part store and clear the code. Turned truck off. Plugged in part store code reader. Cleared CEL. Started truck, and it immediately felt sluggish.

I guess the cat could be clogged, but wouldn't the truck of ran bad before clearing the code?

 

Update****

Pulled plugs and wires, and aside from a little build up, looked fine. Put them back in. Took battery cables off again as well as checked fuses.

Absolutely no way I could get the bolts for the cat off without taking it to a shop. I believe they are all closed, and plus the truck doesn't want to go.

I tried to drive it and it starts fine, but just won't accelerate without shuddering. Kind of feels like it's missing or starving for fuel. You know that feeling when you step on the gas, it revs up, then stops, then starts to rev up again. I had to pretty much ride the clutch to keep it from dieing while trying to make it back to my driveway.

The thing that has me confused is it was running fine before I hooked it up to the code reader. Immediately after, it runs like garbage? Any chance it messed something up? Or is this just a giant coincidence? Code was a P0171 code.

 

it only takes one fuel injector with low impedance to make your engine run like donkey poop....I have one injector takes goes wonky when is sits overnight in a rainstorm, somehow with all the moisture, it just doesn't inject, after a minute of warming up, back to normal, happens very infrequently, unfortunately, the three injectors under the intake manifold are hard to get to, so someday I will visit those with a voltmeter and check impedance, after removing the intake...


Just a thought incase nothing else pans out....

 

Well, me and a buddy started digging around under the hood. Couldn't find anything. I put about 2 gallons of fresh gas in it, since it was low.

Drove it around the block (1 mile loop). Still shuddered, and missed. Pulled it back in, he said maybe it's the coil. Pulled the #3 wire at the coil, plenty or arcing. Then the #2 wire, plenty of arching. Pulled the #4 coil, barely any arcing. Then pulled the #1 coil, plenty of arcing. Pulled the #4 again, barely any arcing.

Let truck idle for about 5 more minutes, drove around the block, and it felt fine. Got on the hwy, felt fine. Pulled up into driveway, pulled the #4 wire again, plenty of arc.

The only conclusions we could come up with were either I had some bad gas, or the coil for #1 and #4 is going out.

I've never had a coil go out. Do they go slowly, or is it just a work or doesn't kind of thing???

 

P0170? Fuel trim issue. If I had to guess (not saying its the issue), I would say MAF. Computer adjusted to signal change as it was getting fouled. Cleared the code, and it's like throwing a dead MAF on it without giving the comp the chance to adjust.
I don't know the procedure to check/clean your MAF, but maybe something you'd want to look into. Probably just remove and spray with MAF cleaner. Unless absolutely sure, test stuff before throwing new parts on as you may just end up wasting your hard earned money. Unless you are rich, then new parts and loan me enough to buy LT for my truck.

 

Sorry, was P0171.
Read out that was printed from Autopart store states:
Air/Fuel mixture
System Lean Bank 1

Probable causes:
Low fuel pressure
Faulty MAF sensor
Cylinder Misfire
Faulty 02 Sensor
Large Vacuum leak

I regularly clean the MAF. Maybe I'm doing it wrong, but I take it out. Spray both wire parts, let dry, then put back in.

 

Ah. Ok. Same issue possibly. Comp learned a failing component, reset comp and it sees it as dead.

 

Makes sense.
Does a coil usually take some time to fail, intermittently working until it finally dies, or does it pretty much just go out?
My other thought was a bad MAF.

Just wanted to check with the forum first hoping someone could shed some light before I start dropping $100 here and there for the wrong parts.

 

Bumping this back up. Truck did the exact same thing today. Cleared the code, truck ran like crap. Sounds like it is missing at idle. Give it some gas and it sputtered bad, and popped a bunch. Then it started to idle fine and seems to run fine. Code popped back up though.

Ran it, same code. P0171. This time the Cat and EVA parts were blinking. I assume the Cat refers to the catalytic convertor, but what does EVA stand for?

Ideas?