Still have P0303 code after plugs, wires and coil

hey guys, I think I bought a lemon. I picked up a 99 Tacoma prerunner and it ran perfect when I bought it. But on my 200 mike trip home I got a cel and wouldn’t get up to 80. Went away a minute later. I got it scanned and got p0300 and p0303 misfire cofes. I replaced the plugs and wires and still idles like poopy. Got the p0303 again so I replaced the coil. Still have the code. Cleaned map sensor and still get a p0303 code. My next guess is an injector or new maf sensor. I’m about to bring it to the shop. Any ideas?

Symptoms are:
Rough idle
Rough starts (had to give it gas to start yesterday after sitting 20 mins)
18 mpg all highway. Most 55mph highway.
P0303 code
Cel flashed at me a couple times
Cruises fine but every once in awhile on the highway it will hiccup once.(happens 2-3 times in my 100 mike commute)

EDIT: foam coming out my coolant resivoir now

Thanks a lot folks
 
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Welcome to the forum. Could be an injector......could be a valve.......definitely a trip to the shop.
 
If the engine is quiet then probly not a valve......I'm just throwing out possibilities and valves have been known to throw that code......as well as EGR valves....worn piston rings.....bad injectors......slipped timing belt.....I'm just throwing out possibilities for you.
 
If the engine is quiet then probly not a valve......I'm just throwing out possibilities and valves have been known to throw that code......as well as EGR valves....worn piston rings.....bad injectors......slipped timing belt.....I'm just throwing out possibilities for you.

Yea, my buddy just said could be slipped belt.
 
hey guys, I think I bought a lemon. I picked up a 99 Tacoma prerunner and it ran perfect when I bought it. But on my 200 mike trip home I got a cel and wouldn’t get up to 80. Went away a minute later. I got it scanned and got p0300 and p0303 misfire cofes. I replaced the plugs and wires and still idles like poopy. Got the p0303 again so I replaced the coil. Still have the code. Cleaned map sensor and still get a p0303 code. My next guess is an injector or new maf sensor. I’m about to bring it to the shop. Any ideas?

Symptoms are:
Rough idle
Rough starts (had to give it gas to start yesterday after sitting 20 mins)
18 mpg all highway. Most 55mph highway.
P0303 code
Cel flashed at me a couple times
Cruises fine but every once in awhile on the highway it will hiccup once.(happens 2-3 times in my 100 mike commute)

EDIT: foam coming out my coolant resivoir now

Thanks a lot folks
How many miles are on it?
Foam in the the coolant that’s not good. What’s the oil look like? Chocolate milk?
 
How many miles are on it?
Foam in the the coolant that’s not good. What’s the oil look like? Chocolate milk?
257k oil looks clean, even coolant looks clean. Not over heating. I just pulled over and saw it was foaming out. I had 3 water bottles with me and put them all in. Drove another 15-20 miles to the next gas station and no overflow
 
Having to give it gas to start it could be fouled spark plug(s) from ??leaky head gasket?? When you changed the plugs were they wet?
No, actually perfect condition. All looked identical in wear. I was contemplating changing them as I was taking them out they were so clean. Even my #3
 
No, actually perfect condition. All looked identical in wear. I was contemplating changing them as I was taking them out they were so clean. Even my #3
Can probly rule out leaky head gasket then......just might be a faulty injector then.
 
Can probly rule out leaky head gasket then......just might be a faulty injector then.
I hope so. But the foamy radiator has me worried. Got another 20 miles to go.
I don’t mind the money and labor working on this thing. Everything is 1/4 price and 10 times easier to work on than my diesels and vw’s
 
I hope so. But the foamy radiator has me worried. Got another 20 miles to go.
I don’t mind the money and labor working on this thing. Everything is 1/4 price and 10 times easier to work on than my diesels and vw’s
Yeah, the foamy coolant might be a leaking head gasket......might be gettin' small amount of air back into the cooling system but not bad enuf to foul your spark plugs or burn off through the exhaust and cause smoking.
 
I'm sorry to say but I would thought that it was a malfunctioning fuel injector but sounds more like a bad head gasket especially after hearing that you're getting gases or foaming coming from the coolant either you got crack in the block
 
I'm sorry to say but I would thought that it was a malfunctioning fuel injector but sounds more like a bad head gasket especially after hearing that you're getting gases or foaming coming from the coolant either you got crack in the block

Welcome to the forum
 
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