I have a h22a in 97 civic that ran fine one minute then next time I started my speedo was dead and the cat won't rev past 3500rpms. Would a bad vss cause limp mode?

 

Could definately be the vss, the speedo will go dead when it fails. Check it
out and see what shape the unit is in and the small piece which rotates. If
the unit is dead i would recommend getting a new one rather than a used
one. They are relatively cheap and a used one is likely to fail in a short
period too. They have a tough life due the repeated heating cooling
cycles in the engine bay. It is usually the electronics in the unit which
pack it in. Also check your codes too and make sure the vss is the problem
before you go replacing it. Hope thats of some help, GL man.

 

make sure the VSS is the problem. Does it hit like a redline at 3,500?

I thought if the VSS went out it would still drive and rev normally, just the vtec wont engage and no speedo.