Rep Power: 318

’01 Ex, 138k miles. About 2 months ago, the CEL light went on and after a scan, diagnosis said I needed a new CAT.

(background info: I am the original owner, however a family member had it for a while though so I wasn’t present during this time where the new CAT was the problem via the code)

Anyway, CEL has been on since then, no decrease in performance/mpg.

A few weeks ago, CEL started to occasionally flash. Not at any particular time, but it would flash while driving. Not only that, I noticed a drop in gas mileage (it normally got around 37 mpg, now it only gets around 31). I took it to my mechanic that I trust, he put in new plugs and cleaned the intake manifold.

Nothing happened. Still got lower gas mileage and the CEL keeps flashing every so often.

So today I took it to another guy I know and trust, he took a look at the car. Checked the plugs, checked the coils, took it for a spin, couldn’t find a problem. He did scan and the scan showed a misfire on all 4 cylinders.

He advised me to first change the fuel filter, and then see what happens. If that didn’t fix anything, he said I might need the timing belt replaced.

I have tried adding high octane gas and a fuel injector cleaner (which actually increased my gas mileage), but the CEL still flashes.

I am also noticing that the engine will occasionally shake while in neutral AND will kind of hesitate off the line.

Bottom line: scan reads misfire on all 4 cylinders and I understand the basics of what could be wrong. I am coming to you guys b/c I’m sure that someone has had this problem before (yes, I have done some searching) and I would like any input/advice on this matter.

Thank you.

 
Rep Power: 270

uh have u even checked the o2 sensors at all? that could b your problem. if u had it say CAT or in need of new cat then y dont u replace it?

 
Rep Power: 318

Well, I wasn't in possession of the car when that code showed up but that was what I was told.

However, if that were the only problem then wouldn't it show up on the scanner now? The only codes that came up on the scan were cylinder misfire on 1,2,3,4.

And btw the CAT wasn't replaced b/c there was never a drop in performance until now.

 
Rep Power: 812

well the cat could be a problem if its clogged. also doesnt seem the mechanics know anything. what does the engine code say now? replace cat? omg forget what they told you, timing belt? fuel filter? theyre joking right?

 
Rep Power: 318

Brother, the codes showing up are misfire cylinder 1, " " 2, " " 3, " " 4. nothing about the CAT now.

Back when the computer was scanned, they said it was an 02 sensor issue. Again, I was not around/driving the car during that time so I didn't see it with my own eyes.

 
Rep Power: 812

okay well a misfire tells me you need to check certain things. is the coolant at the upper level? losing any coolant, smoke out exhaust? what did the plugs look like, normal? maybe do a compression test and see if the motor is okay. are you sure they changed the plugs, and if so which kind? hows your oil look? injectors clean enough? and i dont mean throwing in cleaner, you need to have them sent out for blueprinting or just get replacements. people sell em here all the time for cheap when they turbo. is your fuel pressure high enough? bringing up belts and fuel filters is not the way to diagnose anything.

 
Rep Power: 318

Coolant level is fine, not losing any nor am I getting any smoke out of the exhaust.

Plugs looked normal, replacements are NGK. We pulled them out today to check if they were bad.

Right now oil is dirty, it's due for a change so I will do that this weekend anyway. It is changed every 3k miles, this drop in mpg has been going on before I got my last oil change.

As for the injectors, that was one of the original things my mechanic told me that might be the issue. I'll look into finding some for sale on here (thanks btw).

And I'm sorry but I'm not that educated with cars, so I have no idea how to check fuel pressure or a compression test.

And again, the fuel filter and timing were not my ideas, rather from my mechanic.

As for the problem with the CAT, if that were a problem then wouldn't it show up on the scan? Like I said, all that showed were the cylinder misfires.

 
Rep Power: 812

compression is easy, you can buy a $40 tester and then all you do is remove the intake box, unplug injector harnesses, take out spark plug one at a time and hook the gauge up in its place. then floor the gas and crank the motor 6 times and read the gauge. 135psi is stock normal, but you need to be more concerned that all 4 values are close together like 130 135 132 130.

emissions is tricky, sometimes something might be bad, and no cel comes on. i had a cylinder misfire where the car would start shaking violently on startup and i got no cel except once every 20 times it happened. do this, go drive around pretty hard and warm the car up, then quickly pull over and look under at the cat. if its glowing red, you have a clogged cat. could also be clogged header! but yea since the gas mpg went down, that also could be a bad primary 02 sensor (which would also explain misfires because it calculates a/f ratios). you might even need a valve adjustment who knows. does your engine make any weird noises like loud ticking, growling, etc.

 
Rep Power: 453

based on experience, any time you have misfire codes on all cylinders, its usually not caused by the coils, injectors, plugs. you are not going to experience 4 coils that misfire randomally, same with the injectors. usually an issue is caused by an air leak (vacuum leak), fuel pressure issue, or sensor issue. and as stated above valves out of adjustment or not adjusted properly can also be the cause.

now do you have any other codes besides the misfire codes?

you also may have carbon buildup on the piston tops and this is causing you the issue. like gearbox said, a compression test will confirm that. if the readings are above spec, carbon may be to blame. too low and mechanical issues would be to suspect.

 
Rep Power: 318

1. No noticable noise (ticking, growling) that I have heard from the engine.

2. No other codes but the misfires.

I am going to look into the compression test this wekeend, I will report back asap.

Thanks guys.

 
Rep Power: 0

bite the bullet and take it to honda dude. if your not competent to work on cars let the pros do it. if something sounds fishy or too expensive at one dealer, post back here, then go check at another dealer. good luck.

on another note, im not competent either, i'd pay the money and get it fixed correctly rather than throwing money at plugs, coils, belts, filters etc. but all the guys suggestions in this thread should put you on the right track, then if the mechanics at honda talk to you about it and you sound like you know some ****, they may not screw ya.

 
Rep Power: 812

honda mechanics arent that competent either as ive found out the hard way.

 
Rep Power: 0

god help us all then

 
Rep Power: 812

well when you get your car back with low oil, a ground wire dangling inside the radiator fan, and spark plugs that are loose or overtightened, you have to wonder. im shocked i made the 15 min trip home before i spent 3 hrs to check all their work over again and actually use a torque wrench. and according to the dealer that was their "best" mechanic they put on the job.

 
Rep Power: 318

Well, I just got my car back from a place called Central Honda Authority, a shop that just so happens to specialize in HON/Acuras.

They had it for over a day to run tests, here is their diagnosis:

-new plugs that were installed are platinum, I need iridium.
-all injectors have gone bad
-compression test is normal


Anyone have 4 injectors for sale??????

 
Rep Power: 812

lol. well at least they found the prob. and you dont "need" iridium. platinum comes stock on our cars. i use copper. it doesnt matter. just try some new injectors. you havent been using high octane gas have you? cause above 87 can cause extra carbon to form and also injectors can fail.

 
Rep Power: 318

Thank God you are on line, yeah I kinda knew that iridium wasn't necessary but I didn't want to start anything w/the people there.

As for higher octane, I am sure that this car has been filled up with higher than 87 octane many times (many gas stations outside of the city don't sell anything lower than 89).

The broad at the shop asked if I wanted them to put in new injectors, $85 each.....plus $225 for labor.


RIIIIIIIIIIIGHT.

 
Rep Power: 249

did you check your CAS?

 
Rep Power: 318

huh?

 
Rep Power: 380

Paypal me $40 bones and I'll ship you a set of 4 that came off my 03 EX when I got a new long block that had a fuel rail on it. Very easy to install. direct__products@hotmail.com

 
Rep Power: 249

CAS is the crank angle sensor and if it's bad or not plugged in or something it'll make your car throw those codes saying you're misfiring on every cylinder.