I've seen a lot of threads on how to clean the EGR ports. My car failed smog miserably, but my EGR valve works just fine. It has to be that the ports are clogged. My problem is that I have an H22A1 intake manifold, so the ports are welded over. How should I go about cleaning the ports? Thanks.

 

Drill out the ports carefully, clean ports w/carb cleaner, tap ports, clean more to remove metal shavings, close ports with bolts bought at hardware store. Sounds simple, and it is, this is how I did it on my h22 manifold. Just find the right bolt length and you're all set, 7 bolts I believe.

 

Your going to want Titainum bits. Try and find actual titanium drill bits, not the titanium coated ones.

 

One more thing, I did mine while my intake manifold was off of the car. It might be a little more difficult if it's in the car while you're doing this.

 

yeah i think i would pull it off just so i could clean the **** out of it after drilling ....im thinking about doing this to my h23 and using allen head plugs to fill them in....

 

The manifold is sitting on my workbench completely torn apart (replacing all orings and gaskets).

You say there are 7? I see the 6 on top. I assume your saying I should drill the one out on the drivers side so I can clean the whole length of the port?

What size drill bit should I use? I bought a number 25, but that was before I noticed that my ports were welded in.

I guess you're saying it's not worth grinding down to pull the ports out with a slide hammer huh? Thanks for the replies.

 

I poured in a bunch of Seafoam into the rectangle opening where the EGR valve sits (and goes to the ports). It went strait through and came out the the other end of the manifold. Not knowing how the ports connect to each other inside, am I safe to assume that it's unblocked and no further work is needed?

 

When we get these in our shop, we leave the manifold on. Just remove the EGR valve, shove a shop rag in exhaust hole and stick a hose in the intake (suction) side, with a funnel on the other end. Let the car idle,pour top engine cleaner, combustion chamber cleaner, carb cleaner, or sea foam. As the car idles the cleaner will saturate the build up and eventually pull it through. You will know its clean because the idle will go to about 2000 or die because of a BIG vacuum leak. Bolt the EGR back on and clear the code. Works every time!

 

Sorry I forgot to mention, What code do you have? A lift code? Or a flow code? If you have a lift code, the problem may most likely be the EGR lift solenoid (Honda calls it a frequency solenoid) We see these fail often.

 

This is an OBD1 engine...so no code. Failed emissions miserably due to high NOx. Valve operates freely and holds vacuum, so it must be the ports. I actually drilled one out and there was about 1/8" of carbon buildup blocking the path to the runner. No doubt that is the issue. Just need to drill out the other 7 and find something to plug them back up with.

 

Oh, OBD1 only moniters lift and that would be a code 12, High NOX, EGR produces NOX. Is the EGR valve sticking open a little bit? If the cam timing is off, the NOX will be high. Do you have adjustable cam gears? Are both cams at TDC?

 

Hey, I double checked my books, youre right on with your diagnosis. The plugged ports are most likely the cause of high NOX. And youll never get a EGR code for plugged EGR on OBD1.

 

great info man...thanx.

 

I've tried and tried to get my EGR valve to come off and haven't had any luck breaking the bolts loose. I've tried PB Blaster and several different kinds of tools.

Any tips or tricks from your experience at the shop or special tools?

 

so what would be the symptoms of this. my car runs very very bad and bogs down when my car hits operating temperature. and also if anyone has the easiest way to do this let me know. what size drill bit/what size screws or what they used to plug the holes.

 

Glad you were able to confirm my suspicion. I'll set up an appointment for the referee sometime next week. Hopefully that's the last problem I run into.

 

Sorry, mine came off real easy. Just used a short socket...removed the nut closest to the throttle body, then was able to tip the EGR valve towards the throttle body for more room as I loosened the other nut.

 

Confirmed EGR valve was functioning properly...even tested using the EGR valve from my F22A engine. Car didn't stall when applying vacuum to the EGR valve with either valve as it is supposed to. That's how I was able to determine that it must be the EGR valve. Not sure why the service manual doesn't list clogged EGR ports as a step for troubleshooting emissions failures. Guess it has to do with Honda not admitting it is a problem until after the service manual was created.

 

Well, if the ports take around 10 years to clog, they may not have expected it at all. Sometimes bad design takes a long time to rear its ugly head.

 

You got it! Honda even have EGR access plates on some models. Makes life so much easier.

 

i wonder if your coolant temp sensor is bad? does the car run extremely rich?

 

Doesn't run rich. I drilled one of the holes already. Port was clogged up. I have no doubt that why it failed smog.

 

Make a Write-up for all those who have to drill holes instead of how the 5geners use it. It seems simple but pictures make everything nice and clear cut

 

Does the 92S(F22A) engine need to have this done?
Car is running fine(189K) never thrown a code since I had it(135K)

Would it involve the drilling as well or would a simple removal\inspection\clean take care of it? Doesn't seem that hard to remove. Would local parts place have replacement gasket

 

Windwalker, OBD1 will never code up for a clogged system, the ECU only moniters lift. But there is an old Honda service bulletin for hesitation,stumbling off idle, The bulletin directs you to clean out the EGR ports. They have a repair kit for your car! Comes with a new set of plugs for the intake manifold.