I am looking for the ignition key to my Olds '98. Since I lost the key, I don’t have the resistor value. How can I get a
replacement key otherwise?
Thank you.
Quickest option is a GM dealer.
Otherwise some locksmiths can work with these type of keys and get you going again.
Make two 
I Don’t Have Any Idea How To Do That.
Click the link below and call the toll-free number at the top of the homepage. I’m not sure these folks can help, but they should be able to offer good free advice. At least they should understand what you’re talking about. I don’t.
http://keylessride.com/
Are you sure the resistor value is in the key? Are we dealing with PassLock 2? Lots on the web about Passlock 2 . Spend some “google” time. You will find instructions how to program new PassLock 2 keys (the resistor is in a module attached to the ignition lock cylinder) You will need a correct mechanicaly cut key. Maybe the Dealer that sold your car has key code (for mechanical cutting)
when i was repoing i would go to the dealer and give them the vin they would cut me a key for 75.00. Small price cause i was getting 250 for a car return per profit. You will have to show ownership (title) is the best way.I had repo papers.
I do not know what YEAR of Oldsmobile 98 you have, but ANY locksmith that does Auto Lock service, can fit keys to this vehicle, on site.
Be careful you are getting a real locksmith, refer to www.legallocksmith.com to learn how not to safely be guided to a LEGIT locksmith.
No need to tow it, no need for it to sit behind dealership till its’ turn comes up.
If newer than 1998, any locksmith can access the DELCO secure locksmith area of GM site, and acquire the original key code info, saving some cost, if they have a shop you can get a ride to, alogn with all proof of ownership.
Locksmiths using CODEMAX, LASER 3D or LASER Matrix Retro can produce keys VASTLY more accurate than a dealership could.
Ask Locksmith for the KEY CODE when done, to keep on hand for NEXT TIME.
Jeff
City Lock
2898 30th St
Boulder Colorado