Egr function is about volume of flow. A small reduction in cross sectional area creates a large reduction in the volume of egr gas flow. So I suspect these egr plates need to be kept clean for this super high performance Insight engine to do it’s job at 80-100mpg.

I ended up touching up the egr plate with q-tips and carb cleaner. The carbon is so dense and sticky that using the small screwdriver to get 99% of the carbon out was a mandatory first step! The egr jets (blocks) have tapered holes, so getting into each of them takes a little diligence.

Far better!

I just got back from Fuel Injector Corp in Livermore, CA. The injectors all had the same flow rate and also had an excellent pattern. Robert put 3 new o-rings on each injector. The flow rate that most peopel read about is 145 ml/min. But that’s only at full open. Mine were also checked at the equivalent of 3k rpm, with 43 psi fuel pressure. The seal that goes between the injector and the intake manifold had tiny cracks in it on the lip, at the very top of the seal. So I had to order them from Honda. They are a rare item so it was going to be 3 days. So I had them expedited and they will get here tomorrow for $12 more. The seals were only about $4 each. I could see reusing the old ones, but with 220k miles I am just not going to do this work twice. So the Insight sits for another day. I’ll go get them and the o-rings for the intake manifold in the morning. I may take the egr plate back out since it’s waiting for o-rings anyway and use some solvent and q-tips to polish up the passages a little more. Depends on how energetic I feel. We have plans tonight so I may not have time. Regardless the egr plate is clean and will help the Insight run far better when it’s finally back together!

I decided it was finally time to take out the EGR plate and see how badly clogged it was. I wasn’t disappointed!!

In a couple of places the carbon cutoff all flow of egr gases. This will be a huge factor in the Insights drivability.

Look how high the carbon is piled up on the gasket. Combined with the carbon in the passages made this egr system inoperable.

Another completely plugged egr passage.

That crusty looking egr valve was from another Insight that a guy was parting out. The whole unit was bent. I straightened it in a machinists vice. The pintle was bent too. Now after the Insight is all back together I will swap between egr valves to see if there is any difference.

Just used this small screwdriver for most of the carbon removal and then a paper towel and carb cleaner to wipe of the the very smooth gasket surfaces. I didn’t want to use scotchbrite pads as it would scratch the surface up.

The engine to egr plate gasket part number for my 2002 Insight.

The gasket has sealer bonded to both sides. So reusing an old gasket won’t be as reliable as a new one.

Freshly tested, ultrasonically cleaned, and soda blasted injectors right from Fuel Injection Corp. All new o-rings too.