Rep Power: 0

Please excuse my ignorance when it comes to certain car terms. But I would like to present a problem and see if anyone here might be able to point me in the right direction. I have read through the CEL threads before posting this, but couldn't find much help.

I recently purchased a 2001 Civic Ex with 131k miles that ran great and looked to be a good buy from a private party. The second day the CEL came after reaching about over 55 mph, and 50 miles of use. The car ran great, no hesitation, no jerking at any speeds. I saw that previous owner had replaced the 4 spark plugs and coils recently, so I took it into a service station and was told it was random misfire and with these codes:
P0300 Random/Multiple Cylinder Misfire Detected
P0301 Cylinder 1 Misfire Detected
P0302 Cylinder 2 Misfire Detected
P0303 Cylinder 3 Misfire Detected
So the shop said that the wrong plugs were used so they put in the right ones and reset the CEL. Sure enough after 50 or so miles the CEL came back on when I was cruising on the highway. The same shop checked the coils, and then swapped some to see if the problems will follow the coils. The CEL came back so the ran a compression test and it looked fine. They couldn't figure it out and recommended maybe reflashing the computer or replacing the computer before going deep into the engine due the cash required for such a big job.
I run it over to another guy and he thinks cylinder four is the problem because this time the code came up P0304 and random misfire. He is a family friend of my brother in law and after the CEL came on after he reset it, he kept it over night to really dig into the car. He now tells me that the engine is having a hard time "maintaining pressure" and will eventually need to be replaced sooner rather than later. He offers to replace the engine with the same make and model engine (with only 45k miles on it) for $1500. He is doing this at this low rate because of my brother in law who has helped him out greatly in the past. Another mechanic backed up the service shop about the computer possibility, but said a dirty solenoid might be the cause or the feed back wire might have a short.

Does it seem worth it to replace (upgrade mileage wise) the engine as the car runs great and considering I only paid 3500?

Also I would have to find the problem to the CEL before the next inspection in 11 months.

Thanks for any feedback, even "Use the search functions, you idiot" as long as you attach links.

 
Rep Power: 233

What kind of "pressure " is it losing? Vacuum pressure? Compression? Compression test was good so, how could it be losing pressure? If it is an internal problem (loss of compression) usually it's cheaper to R&R the engine. These engines only run about $500 salvage.

Try a top end cleaner and have the timing checked before proceeding.

 
Rep Power: 0

How did you know the compression is still good? Did you conduct a leak down test?

 
Rep Power: 0

I spoke again the original service shop for more details:
When the car first came in it had a misfire in all cylinders and random. They saw the wrong plugs were used so they swapped them.
Then CEL came back with misfires in cylinder 1 and 2 and a random misfire. They swap coils with 3 & 4 and when the CEL came back on the misfire codes were now cylinder 1, 2 & 3 and a random misfire. They did a compression test and it came back good. They are now thinking the computer might need to be reflashed, replaced or checked for shortages.

The pressure problem was only mentioned by the second mechanic and for now is being dismissed as not related to the CEL misfire issue.

The third mechanic got the same codes- random, 1, 2 & 3 and tells me to check the vtec solenoid screen to make sure it is clean because cylinder 4 is fine and is the first cylinder after the solenoid.
He also gave me some diagnostic info about the misfire. It occured at 38 mph, 2635 rpm, 62%

So now I am back asking for help with the misfire CEL problem and not the pressure issue.

Another concern is that the car runs great, but with the CEL on I might mask some serious problems.

Thanks

Btw this is a great site, I'm just glad I stumbled upon it.

 
Rep Power: 233

Check:
-fuel pressure
-each injector clicks
-EGR
-VTEC
-valve clearance

If none of those is it then go to the dealer and get the ECM/PCM re-flashed or replace it (I would try a $50-100 salvage one first).