Hi all,
I have a 93 accord EX with 170K, auto
Just go back from my emmision test and the car failed. It did not pass

NO - Carbon monixide is reading too high 1.62 limit is 0.71
NO - Nitrogen Oxide is reading too high 2239 - limit is 910

No check engine light is on

Oxygen sensor is new
Catalityc converter is new - after market

What could be causing this?
thank you all in advance

 

Try this, it worked on my old 93 integra time and time again. It was completely aftermarket from the headers all the way back.

http://www.autobarn.net/ch05063.html

 

Don't they have to tell you WHY it didnt pass & how to fix it?

TRY this first, before spending a grip of cash.
Carbon build up is one of the leading causes of emission failure in hight mileage cars. Go to an autozone, or any auto store and purchase SEAFOAM.

Its about $7 and its easy as hell. It rots away to carbon build up and cleans your EFI system.
Note: Put the seafoam through the injection system or the breather lines that go into the EFIS. This is the most efficiant route to getting everything cleaned up.
Then drive it on the freeway for a few miles.

 

yep its got to be carbon build up
EGR ports are clogged
Trottle is dirty as hell too I bet

I dont know about seafoam
I been looking into that
is that safe?anyone done it on 90-93 accords?

 

check your EGR valve that will throw a high NO number

 

It sounds like you need to start with a good tuneup...plugs, probably plug wires, fuel and air filters, PCV valve and clean out the throttle body and EGR systems where it feeds in. As the others have suggested, the EGR system itself probably needs a good cleaning and the EGR valve inspected.

You may want to consider having the fuel injectors and intake valves cleaned professionally or use one of the kits that plugs into the fuel rail. Carbon buildup on the intake valves can cause the system to run less than optimally. (I use a fuel injector cleaner that the Honda dealers used to carry called BG 44K (I believe that it is basically a can of Techron concentrate that is in many gasolines) that you just throw in the gas tank every other oil change or so to try to keep things clean on a preventative basis.)

Did they test your vapor recovery system from the gas tank? I do not recall if my '94 had a vapor recovery cannister in the engine compartment or not. Check and see.

 

Seafoam works. I used 1/2 of the can though the vacuum line, 1/2 for the gas tank. Works great. I don't use it often.

Try some of these to help lower your readings...

Clean EGR ports,
Change air filter if it's like SUPER dirty.
Seafoam
Throttle Body
Spark plugs (if needed)
Wires? Ever changed it?
Cap and Rotor. If you want.

 

Hi,
Can you tell me where to put SEAFOAM at?
1- in injection system? where at?
2- EFI system? what does EFI stand for?
3- Breather line?

Thank you
Joe M.

 

^like someone said

EGR ports yO