Toyota MR2 Message Board - View Single Post - 20V MK1 Engine Swap pain in the butt black top conversion

mr220v · 10-12-2007, 10:05 AM

You have codes 21 and 42. Code 21 is for the O2 sensor, and 42 is for the vehicle speed sensor.

21 won't cause the CEL to come on. 42 will under certain circumstances. Usually you have to be revving above 5000rpm's for more than 30 seconds or something like that. You must be cruising at 100+mph.

Code 42 doesn't cause the ecu to go into limp mode, it only flips on the CEL. The advantage to not having the speed sensor hooked up is that you can exceed 120mph. With it hooked up, you'll be speed limited to 120.

10-12-2007, 10:05 AM	#7 (permalink)
mr220v Beams Owners Group Join Date: Mar 2006 Posts: 2,529 Thanks: 13 Thanked 176 Times in 147 Posts iTrader Rating: (11/100% )	You have codes 21 and 42. Code 21 is for the O2 sensor, and 42 is for the vehicle speed sensor. 21 won't cause the CEL to come on. 42 will under certain circumstances. Usually you have to be revving above 5000rpm's for more than 30 seconds or something like that. You must be cruising at 100+mph. Code 42 doesn't cause the ecu to go into limp mode, it only flips on the CEL. The advantage to not having the speed sensor hooked up is that you can exceed 120mph. With it hooked up, you'll be speed limited to 120.