I have code 21 on my newly purchased 91

[CajunKenny]

Ok. So I replaced my wrecked 87 with a 91 this weekend. I drove the 91 home (400 miles or so) without any issues. Then today I get a code 21.

Could it simply be a bad O2 sensor...where do ya'll recommend that I begin?

Thanks...

 

[jdub]

Start here:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?S=FI&P=119

 

[Team_Yota]

A code 21 is your main oxygen sensor