I think that a clear example of bias is to be found in this passage:
For the Scripture says to Pharaoh: "For this very cause I have let you remain, that in connection with you I may show my power, and that my name may be declared in all the earth." -Romans 9:17 NWT
The Greek text here reads εξηγειρα σε and is to be translated as "I have raised you up" with God as the subject and Pharaoh as the object. The passage thus means that God "raised up" Pharaoh, either in the sense of bringing him into existence or in placing him in power (cf. BDAG s.v. εξεγειρω 4 & 5), for the express purpose of destroying him so that the whole world will know the power of God. However, the view of God in this verse, as well as this chapter as a whole, which emphasizes man's utter lack of power before God's omnipotence, runs counter to Jehovah's Witnesses as well as other Christian's conceptions of free will so that it must be minimized and interpreted in keeping with those views. Jehovah's Witnesses for their part have chosen to impose on to the text their particular interpretation rather than try to interpret the words as they appear. They then attempt to justify this interpolation with the following footnote:
"I have let you remain," J17,18,22; ?AB, "I have raised you up"; Ex 9:16 in LXX, which Paul here quotes, "you have been preserved."
Their citation of three manuscripts here (?AB), which is actually the same reading of εξηγειρα σε as their base text of Westcott-Hort, shows that they clearly know what the Greek text actually says and how it is to be translated, but instead of following that Greek text they have cited 3 J-References to "confirm" their translation and claimed that Paul is quoting the Septuagint which reads "you have been preserved." In point of fact, however, Paul's citation of Exodus 9:16 here departs from the Septuagint's translation at several points, most importantly in not following its reading of διετηρηθης ("you have been preserved") but instead writing εξηγειρα σε ("I have raised you up"). The J-References for their part simply import over the Hebrew text from Exodus 9:16 thus reading he'emadtika (hiphil perfect, lit. "I made you stand") and not "I have let you remain" as their footnote maintains. However, even if the J-References had read "I have let you remain," these translations from 19th and 20th century would not constitute any evidence that Paul's own wording is to be overridden here. One should note that Paul's word choice here in fact brings his citation of Exodus 9:16 into greater conformity to the Hebrew text than the passive translation of the Septuagint and this may in fact have been the reason why his citation does not follow the Septuagint here. One should also note that Paul's word choice is serviceable to his argument made through the context as a whole where Jacob was chosen over Esau "though they were not yet born and had done nothing either good or bad" (Rom 9:11), election "depend[s] not upon man's will or exertion, but upon God's mercy" (Rom 9:14), and men are "what is molded" by God the "molder" and thus have no right to ask him "why have you made me thus" (Rom 9:20). Thus the ultimate reason why the New World Translation is translated the way it is here is simply to avoid the unsavory conclusion that this passage teaches that it was God who made Pharaoh the way he was.
-Mebaqqer