dzungductran

My 02 Acura MDX engine light came on one day so I took to the dealer. They said my gas cap was not tight and they clear the code. But the gas cap looks fine to me and it clicked several times after I put in new gas. But engine light went on again, I took it back to the dealer and they said that they need to clean the EGR ports/valves because I used bad gas. I used premium Costco gas. Is this true? it costed me $114. Now the light is on again before I could empty my gas tank with Costco gas in it.

Is Costco premium gas same as other premium gas? It has a sign with 92 octane on it.

Duane_in_Japan

You need a shop to have an enhanced scanner that can tell you what the dealer can tell you, if you have an evap type code then there are lots of tests to do, the gas cap is number one code blinker in evap systems, buy an OEM gas cap and try again. After installing your new Honda only cap and making it click at least three times then go get your codes cleared for free at Autozone and try try again. That dealer does not know what they are doing, they need to show you (or any shop does) what the freeze frame data was with your code, ask for it next time you want to pay to get the code checked out the right way.

97 TYPE-R 312

Costco doesn't cheap the system. What they buy will represent each specific grade. They buy gas to save the member base $$. I'd give it another shot. If it happens twice, that region might have a problem, so it wouldn't be just with Costco.

-Victor

Cory man

The MDX and many of the other 3.5 J series Honda engines have previous EGR clogging problems. The MDX you have actually has an inspection plate under the engine cover on top off the intake manifold. The dealer wasnt totally correct in saying that the gas was the only reason for the need to clean the ports. There are lots of factors that combine to cause the carbon buildup problem. Do yourself a favor if you dont care for that dealership dont resort to Autozone. Anyone who thinks Autozone knows more than the dealer should think again.

Duane_in_Japan

You could pay a few bucks at an independent shop to have them look at secondary spark on the oscilloscope while applying vacuum to the EGR valve and watch what happens to spark in the cylinders, if you have clogged EGR ports then they will see it. Not all will clog up exactly the same and one or more may still be passing EGR Flow, it can be seen. The car should normally stall out with vacuum applied to the EGR valve, if not then you have clogged ports to some degree, if no stumble at all then the ports are completely clogged. Lots of search material for cleaning them yourself.

I just read your original post again, for $120 I would have the dealer show me what I just said above, do the cleaning then show me the engine die after the cleaning, then guarantee that this was your problem and if not the problem then get a refund for improper diagnosis, it the law. They did say cleaning the ports would fix it right. Remember, you are the customer and you have rights so they must diagnose it right, this will be their second shot at this fix, correct. That is not too much money.

Next issue, ask what CEL (MIL) OBD II Emission warantee is on this vehicle in your state, most are extended and is the EGR System problems covered???? Dont take their word for it, do some more homework. This is such a bad Honda problem that there has to be a TSB on dirty ports and TSB repairs are free also. TSB's are free to the public via government EPA websites I think, they are free someplace, NHTSA???

Cory man

The newer EGR valves arent vacuum operated. I once had a phone call from an independent shop that wanted to replace all 6 ignition coils on an MDX because all cyl's had misfires. Any Honda/Acura tech knows to look at the EGR valve lift and see if the ports are clogged. If you want to have your time and money wasted take it to an independent. If you take it to the dealer 9 chances out of 10 they know the problem before they even look at the car. If the check eng light returns pay the dealer another visit and have them retrieve the code. If its not related to their repairs and wasnt due to anything they did(if you recently got gas and left the cap loose) then you cant be upset.

BTW Honda redesigned the intake manifold on the j35 to fix the EGR clogging problem. From what I have seen the new design works. In the cases that it does get clogged they are extremely easy to clean.

Duane_in_Japan

Kewl, newer Hondas dont use vacuum control, can I assume that a bidirectional scanner will activate the EGR valve in percentage incremental steps? If what you just said is true about the dealer and the new intake manifolds then why does the original post say they want to clean the ports, can bad Costco gas plug up an unplugable port due to its newer design.

All in all, this dealer should have recommended this as part of the real repair the first time and given a reminder to click the gas cap closed several clicks just to be sure. I am not sure but how can an Evap code (gas cap) be related to an EGR flow problem. As you stated any dealer should know exactly what the problem was just by looking at the code, well I guess this dealer didnt. Dealers have noob techs too.

Sorry for thinking the EGR was still vacuum operated on this model.

EDIT:

Read original post yet again, it looks like you DID get the EGR ports cleaned for $114, is this correct and this will be your third trip, its time to carry your receipts back and ask for a new estimate STOP, get a refund on previous work STOP, think about letting them touch your car again based on the third estimate STOP, either give them the work or take their estimate someplace else and have the same work done or a real (emissions / smog) diagnostician figure it out using your previous information as a guide.

How does this system read EGR Flow, with a thermistor???? Low flow, low temp change, code set. CAN YOU PLEASE LET US KNOW WHAT THE CODE IS, if the dealer wont tell you the info that is rightfully yours to know then go to autozone and get it pulled for free. Then we all can carry on with getting this thing fixed.

01usjdmr

You need to post the specific code they are saying you have, maybe have the dealer show you. It sounds as if you have a tech working on it that don't know what they are doing.