i feel that i have been duped at my dealership recently. i had an efi service done to my '98 4runner ltd at 104k miles, then it was recomended again at 129.5k, then the check engine light came on for the first time and the catalytic converter was bad, so i was told, and i apparently need another efi service at 134k, could this be possible? this is all at a toyota dealer. any feedback would be appreciated. thanks in advance...

Depends what the "efi service" involved. The "brain" of the efi either works or doesn't. The injectors themselves can clog but they shouldn't need to be cleaned that often. Off the top of my head I'd say you're due for an O2 sensor with the mileage you're at. That would cause the check engine light to come on and would act like crappy efi/injectors.

The EFI service, if done properly, is a chemical dispensed in an I.V. like fashion, designed to remove varnish, carbon, and other debris from the fuel injectors, throttle body, intake manifold, and intake valves. Think of it as angioplasty for your fuel system. It makes a great difference, but only needs to be performed every 30,000 miles at most. Many things can cause sputtering, especially if your check engine light is on. The most common culprits are the oxygen sensor (California vehicles, it's known as the air/fuel ratio sensor), throttle position sensor, temperature control sensor, vacuum switching valve, and charcoal cannister (look for codes P0440, 441, 446). Another mischevious culprit causing the check engine light to come on is a random misfire code, result mainly from a failing coil pack. A misconception that many people buy into is using too high of an octane gasoline for their vehicles. If yours is designed to run on 87 octane, stay with that octane. If you start getting a constant pinging, move up an octane and look into a tuneup. Besides wasting money, running a higher octane gasoline can actually harm your 02 sensor. Higher octane gasolines have a higher ignition point than the lower grades, thus when burning them in a vehicle not designed to run on them, extra unburned gases go through the exhaust, triggering a premature failing of the 02 sensor. If properly maintained, the 02 sensor should last over 100k miles. Common sense things such as keeping your engine tuned and filters changed should result in 100's of thousands of miles of worry free driving. I see it every day. Erick Faust Service Advisor, O'Brien Toyota/Scion Indianapolis, IN