Does a defendant have to have a certificate of probable cause to challenge a Bargained-for sentence?

cause if the challenge to the sentence is in effect a challenge to the validity of the plea. ( People v. Buttram (2003) 30 Cal.4th 773, 781782, 134 Cal.Rptr.2d 571, 69 P.3d 420 ; 1237.5, subd. (b).) In determining whether a certificate of probable cause is required in order to challenge a bargained-for sentence, " courts must look to the substance of the appeal: "[T]he crucial issue is what the defendant is challenging, not the time or manner in which the challenge is made." [Citation.] Hence, the

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