OBDII Code 302 HELP

Hi all,
sorry for the long post, just want to give all info.
2000 tacoma 2.7L 115K miles
Engine started running rough. idle very jerky. smell of unburnt fuel in exhaust. multiple codes with 302 as one of them.
1. compression check, # 2 - 25psi, all others 150psi, took head off, burnt valve, replaced. now all 150psi.
STILL rough idle with code 302 only,
2. Pulled spark plugs, # 2 dirty with unburned fuel, switched with # 1 plug, reset code, No change # 2 still no fire,
3. Ignition coil pack, switched # 2 with # 1, NO change
4. Checked all wiring harnesses by turning over motor with no plugs in, all four harnesses produced spark. All four ignition coils produced spark, all four spark plugs produced spark.
5. Pulled crankshaft pulley, It is in excellent shape, key square, no slop
6 Pulled all injectors, cleaned, put back in, No Change
7. Switched # 2 injector with # 1, No Change
8. Pulled ECM out, cleaned connections, No change
9. Replaced vacuum lines, No Change
10. Followed wiring harness back about 1', no obvious broken wires
11. Light a match collect insurance... just kidding, but jeez this thing is killing me.
Now truck will idle with no codes, when run up to 2000rpm sounds good, but after 15 secs, check engine light flashes, code 302
Anyone with any ideas, I am getting desperate here
thanks Alan

 

brought 02 sensor about 3 years ago the one before the cat. This would give a misfire code? Don't understand the logic in that one. thanks for the help

 

After market cats have been known to last only a year or two.

 

Hows the valve clearance on #2 after the valve replacement?

Also, may be time to break out the multimiter.

 

Sent you a PM

 

Ok stuck at work for two days, will check compression and do leak down test when I get home on tuesday.
thank you for all the suggestions and links
alan

 

Hi all, just wanted to thank everyone for their input and suggestions. Doc Brown nailed it with the valve clearance tip. When cold, compression was great. but after warming up the valve length expanded causing it not to seal. This explains why there was no code at an idle, but when reved up for 15 -20 seconds the engine became warm, valve stayed open and check engine light flashed. Also why truck would seem to run good right after I started it, but then progressively became rougher and not idle well.
To all members, this is the best site I have found and thank you to all again. Hope this helps someone else with any problems they have.
Alan

 

Glad I could help.

-Brian