Hey guys, this is my first post.

I have a 2002 acura tl type s with 314 000 km on it. The story goes as follows: the car had been sitting for 2 weeks at 1/4 full with regular gas. When I got back into town i started the car to make sure all was good (main concern was battery, started fine). However, the next day when i went to actually take the car out, it was hard to start, studders, and idles rough. When i accelerate its fine and give it gas in neutral its fine, but at idle it's really rough and studders. If im driving along and hit a red light and stop fast enough, the card would completely shut down. I immediately put 94 octane in there and it improved a bit (wouldn't completely shut down when i got to idle, just really rough and studders). Got it scanned and the codes showing up are P0300 through to P03006, as well as P1399 and P0401. I tried resetting and after this I only had misfire of cylinders 1, 2, 3, 4. I then switched the coils of 4 and 5. After resetting again the codes that showed up this time were 1, 2, 4, 5, 6. As I drove along for a bit, all cylinder codes for misfire back on. The mechanic isn't really sure and suggested replacing all coils. I don't think that is the problem. I inspected the coils and they looked good inside, not burnt. I changed the plugs six months ago to NGK iridium, so I doubt its those. Could the EGR be the cause of all the misfires? Any suggestions on how I should proceed? If i can DIY i want to go that route i already put 1500 into rebuilding the tranny, spark plugs, water pump and some suspension issues. Your help is greatlyyyyy apprecaited.

Kindest regards,
Ravi.

 

Dont go replacing all the coils (and FIY you cant look at them to see if they are good). Clean the EGR ports, Put some seafoam in the gas and Go out and drive it like you stole it for a little while see if it clears things up. Dont run regular gas in the car. These cars dont like to be parked for long periods of time.

 

Yeah, ^~^ as Fsttyms1 suggested.....try some quality brand fuel system cleaner in the tank. Clear the codes.

The site's 2nd gen DIY's sticky has tips on cleaning the EGR passageways.

You may want to consider having the electrical system load tested, as our cars get finicky when not supplied their juice. Also inspect grounds. Check electrical wiring, fuel injector connectors and vac lines.

If the misfire problem persists, you may have to buy one new coil and the proceed to replace one coil at a time until you find the bad one. There are many posts available by doing a "Search" for the coil packs and testing.

 

Does the seafoam just go straight into the fuel tank an that's it? I think I remember seeing a step by step on how to clean the egr I will try tht as well, I did inspect the coils and they look good not burnt or anything. Thanks again

 

You should go buy 1 coil pack ( like 3.2TLc said ) an which then out one by one to see it make any different. I had this problem few month ago. i had misfire code on 1,3,4,5,6. end up being just 1 coil pack. Also can you smell gas burning? if so they more like bad Coil pack

 

Yeah, you can put the "Seafoam" directly into the tank. There's other methods using Seafoam to directly clean the intake through the vac, but for now .....try it in the gas.

The coil packs can appear good, but still possibly be bad internally.

 

I would recommend the coil pack change like mentioned above. One of mine went out and I was getting codes for misfires in all cylinders as well. Just buy one from an autostore, they usually have them in stock and it should be like 50 bucks for one. Just unplug a coil pack (one at a time) while your engine is running, and if your engine starts to run way more rough (shakes a ton more) then you know that its working. If you unplug one and dont notice a difference, swap in the new coil and you should be set. It took about 20 minutes and the only tool you need is an allen key (if im not mistaken). I would definitely recommend giving it a shot!

 

This method Only works if one has failed. Many times you will get the random misfire code but all the coils are still firing enough while idling to not not have a change when unplugged. Hence why we recommend placing the new coil one at a time on the engine resetting the ECU and take it for a drive to see if it comes back.

 

Hey Raviasi, the "P0401" code that you earlier stated was being displayed with the "misfire codes" .......could be causing you issues. That code is for the EGR passageways being restricted and resulting in the "EGR Insufficient Flow Detected" DTC. Check out our DIY sticky for cleaning the EGR passageways within the intake. There are also many other related posts which can be found by using the site's Search feature. Worth the time and effort if never done !