EGR Vacuum Modulator -- Does this Filter need replacing? (pic)

I have a 96 Tacoma 4-cyl (2RZ-FE engine) that I'm getting ready for a smog check. Two years ago, the NOx barely passed at 15 MPH. I removed the EGR valve and cleaned the carbon out as best I could. Next I plan to use some Seafoam.

Anyway, there is an EGR Vacuum Modulator that attaches to the EGR valve. Remove the green cap and there's a filter inside. As you can see, the filter is falling apart. One side is coarser than the other.

How do I know if the filter needs to be replaced?

 

For just a filter... I would take a pressed felt [like what Stihl uses for some of their string trimmers to filter carb intake] and trim to fit with a sharp scissors. Make sure diameter is a snug fit. BUT: the diaphragms tend to go before or around the time filters are an issue, which is why this part is unobtanium. Since you struggled through smog, best bet is replace the modulator, and clean ports free of carbon. EGR's generally don't go bad - either there is carbon restricting flow, or the VSV [connecting vacuum signal between the modulator and egr valve] is going bad. I took the opportunity to clean carbon on my 5vzfe around 200k miles as I was replacing valve cover gaskets and port was choked down to maybe 1/16" - a good 90%+ occlusion. You have to remove egr and throttle body to not puke carbon into the engine. Replace any hoses showing signs of cracking - it tends to show first around fittings or under clamps. Some may just harden with age and be a loose fit which is deceiving just looking at it. Good luck!