Vdub328

I need some advice as I have an interesting set of issues on my 2003 6speed. First, some background information, I purchased car three months ago 145,000miles. Everything was fine then marbles in a can on deceleration.... Bad precats, fixed them. A couple weekes later I'm getting a slight hesitation when accelerating medium to hard from say 2500rpm. I researched and found a tsb for the MT with an issue like this. I didn't go to dealer to reprogram ECU but I tested maf and it's good...I then began to get a p0300. Wonderful! I bought six OEM coils and would wait it out as the code would go away after every three or so days...I then started to randomly get the p0303 code...OK I thought now we are getting somewhere hope it's the coils so I bought plugs and new plenum gasket and decided to tear into it. Five of the plugs were perfect they were Bosch fr8mpp30.....cylinder three was in photo below....I them tested the coils that were in there and all read 1.6ohm they are denso OEM equivalent...as I'm doing the job I'm nervous before pulling cylinder three as I already seem to know where this is headed and sure enough the plug in three appears as below. No oil on it just carboned up with debris not to mention the gap is huge....now im really nervous when I get the compression tester out and low and behold 90 pounds in cylinder three!!! Spray some Yamaha starting fluid in there up to 120 and there it stays! Wonderful! Cylinder five miraculously has the highest at 168, all others high 150s low 160s.
I put new plugs in (go ahead noob Lynch me hang me whatever) Bosch platinum's, button it up and go for a spin. Holy **** car feels like it did back in 2003, no hesitation, back to the insane pull and of course that feeling of yes THIS IS WHY I BOUGHT THIS CRAZY MACHINE!
Next morning drive it again and it was fine like night before. I stop and shut car off get in and go up to a light and it bumbles again! See immediately comes on! Pull the code and low and behold p0300 and p0303 again. Now the car drives worse than before, and I don't dare go into 5th or 6th as ses light blinks when accelerating in those gears and sounds like a backfire underneath when pushed in those gears!
OK I know this is long but some more background information, the valve cover on both banks is dry and no oil whatsoever on or in any spark plug. Did I ruin cylinder three with precats? I know i should've used NGK plugs but do they make that much a difference in now my car runs horrible on newer Bosch plugs? I did not do idle air relearn after the install of the plugs, should I do this? With 120 psi in one cylinder, should I rebuild, swap, or torch the car? If I put NGKS back in there will the car run almost normal and just say f it and just drive it?
Sorry about the long post guys but I've been searching and searching and cannot find anything specific to mydrives. The car has no mods, but still has original main cat, is this causing the high rpm in 5th 'backfire' sound after repeated high rpm high load drives? I am planning on either gutting main cat or just running straight pipe.
I appreciate all the help guys and I do plan on keeping the car. I've put too much money into it in such a short time on other minor (new cluster--guess why-- and other odds and ends) issues. One more thing, the car was running OK right before the new plugs were put in aside from a hesitation and a slight shaky 750rpm idle. Oh yeah it burns moderately for a 5.5 gen no leaks no smoke, no oil in intake manifold and im still tryimg to find where it goes! If anyone needs more information to help me decide what to do I will provide. I am pretty mechanically savvy but this has got me stumped!

Mattx

iTrader: (2)

When you say you tested the maf how did you test it? I'm assuming with voltage tester? 120psi on cylinder three isn't good. So I right away would say that's the hesitation/lack of jump. The fact you have a blinking ses is not good at all. That's the car saying you must stop and fix immediately. You have no other codes correct?? If so I'd say that it's time for a new motor/rebuild. You have proof positive it's got low compression and you're getting a blinking ses with the same code for same cylinder with low compression.

Vdub328

Maf was tested with gst ~5 g/s at idle and has appropriate level upon acceleration and wot. Blinking ses comes on after new plugs under heavy load in 5th and 6th

NmexMAX

iTrader: (22)

Gotta be them plugs though.

Blinking SES = Multiple cylinder misfire, that’s the problem and evidently in cyl 3. Have you looked at it since this second problem came up?

mclasser

Yeah those plugs don't belong in these engines.

Driving around with a flashing SES is a quick way to destroy your CAT.

Vdub328

Yes if I wasn't clear in the original post I just tore into the car two nights ago to do the plugs. Cylinder three has 120psi of compression and had the plug in the picture. Does anyone have bad experiences with plugs other than NGK or anything similar to this? Also engine swaps.....I've heard a murano 2005< may be the best bet donor wise as far as cost 2007 altima best bet period....

I am going to reinstall ngks and see if that corrects my current issue of the blinking ses in 5th and 6th. The funny thing is, is in the first 4 it revs nicely and has no driveability issues other than the slight rough 750rpm idle. I know a swap/rebuild will need to happen if I plan on keeping the car for awhile. I'm guessing allmotor forum would be the place to browse for getting information on this?

Child_uv_KoRn

iTrader: (7)

Engine is toasted, but I have no doubt that you can limp along with proper plugs and 50 weight oil.

If you replaced the precats, they're just going to clog with that kind of oil consumption. How long it takes is anyone's guess, but that's some hardcore oil burning.

NmexMAX

iTrader: (22)

09 swap is THE best for power, but 07 is a close second and may be the best at this point.