John Coody

I removed the fill plug to check the level in our 2004 1500 Silverado. thinking it was low so i filled it up with 75-90w. it came out of the hole. Put the plug in. reading up on this topic i found out it might have synthetic lube in it. Question, will it hurt to top it off with regulator lube or should we change it out? I did stick my finger int he hole but didn't get any on my finger thinking now it might be synthetic. Any suggestions? great site a lot of info here! Tks john

I will try swapping them and see what code i get. I thought of spacing the o2 out, It doesn't look to hard to do. thanks, both of yall for the help!!

looking for suggestions on checking out cat. convertor. was told maybe temp. sensor could be bad. don't know how to test. any help would be helpful. Thanks!!