I just went about changing my fuel filter on my 97 for the first time in about, I'd say like 30k miles. Now I noted in the fuel pump thread that I am heavily known to run my tank down till the truck is spitting and sputtering. When I removed the old filter I noticed it was clunking inside . So I took my trusty air saw and cut it open slowly. When it was in 2 pieces, the filter element simply fell out of it. The foam crap that had been adhered to one side of the filter had broken down and it just fell apart. So that means that crap went through my fuel system . Not to mention that this also means that for god knows how long, I've had NO fuel filter. And to top it off, when I removed the filter, black crap just poured out of it. It was nasty. So I threw on the new AC Delco Filter, wrote the mileage on it, and poured in a bottle of Chevron Techron fuel system cleaner in the tank. My intermittent rich condition suddenly makes sense. Crap was in my injectors and making them stick So in the end, Change your damn filter, and use AC Delco, not aftermarket junk. The filter element on the aftermarket filter was even crushed. Looked like it clogged and couldn't take the pressure so it crushed and broke off.