In "Walk Like a Man" we see that Chris has become little more than a joke to not only most of his fellow made guys, but he's even treated as a lightweight by Tony. He might be a Captain, but his word holds little clout, authority or respect. He's kicked out of a meeting between Tony, Sil and Bobby when he comes to complain about Paulie stealing from his father-in-law, and later, after he's had a few drinks at the Bing and is waxing philosophical about his daughter, Paulie remarks how she'll end up working at the Bing, and everyone, including Tony, laughs. He's a Capo, but he might as well be a nobody.

He goes to his old friend JT's house, and says how he's done, and he could bring down the entire operation with one phone call; he glamorizes how Gravano is living large down in Arizona, and how Arizona is close to Hollywood and that he knows and has done stuff that could have a lot of complications for a lot of people. When JT shuts him down, Chris kills him.

The very next episode, Chris is driving Tony again, and is notably wearing a ballcap, something we hadn't seen him wear since Season 1. He's somehow gotten himself back high enough in Tony's esteem to attend a high level meeting between Tony, and Phil Leotardo, to discuss asbestos dumping.

On the way back, where Tony is hawkish about dealing with Phil, Chris insists Tony should let Phil get what he wants in this instance.

I think there's evidence here that he flipped between episodes, and was wearing a wire:

1) He's utterly done with Tony and the family as of the last episode and is talking enthusiastically about life in WitSec.

2) It's shown in Season 4 how they no longer use wires for informants, but instead have a microphone hidden in a ballcap. Jack Massarone for example wore one. ...Suddenly Chris is wearing a cap again after how many years?

3) Somehow, a disinterested, disgruntled Chris got back tight enough into Tony's graces to be at a Boss level meeting? Why would a guy like Chris, disgusted with his life in the Mafia, push himself back up the ladder unless perhaps to get as close to the action as possible so as to inform?

4) Chris urges caution and to deal with Phil in an amicable way. He urges Tony to meet Phil's demand. We've seen time and again that rats on the show aren't allowed to take part in violence and many of them as rats play the role of mediator, advocates of peace, to try to ensure violence doesn't break out or involve them (see for example Albie in New York).

I think between episodes, Chris made a phone call to the FBI, got his cap/wire and worked his way back into the inner circle, hoping to put Tony away and start his new life 'living large' like Gravano in Arizona.

Sounds weird i dont think so, cuz chrisi loved tony, you forget what happend with aid ? If he wanted to leave the life he as a mobster he would have done it with aid already. So in my opinion its sounds weird

Yeah he chose the life over his girl I just can't imagine him flipping.

exactly me too

I thought it was obvious that towards the end of season six just before Chris died that he hated Tony, and was full of resentment towards him. All he did was complain about Tony.

Tony also could no longer stand Chris. Tony realized he wasn't going to be the leader he tried grooming him to be. He worried that any day Chris would flip. He was a junkie, and it was seen as a weakness. He had given him a chance to be clean, then Chris was continually teased about his sobriety. He couldn't fit in with the guys anymore. The main reason Tony kills him when he had the opportunity was because deep down he knew it was inevitable Chris would flip. Which is why he felt so relieved after His death.

I think chrisi could have been a great leader, but the drugs ruind him, also the not so good relationship with paulie.

If he doesn't die it could have made a great plot for another season. He and Carlo jumping to the Feds and then testifying against Tony and New York would have made for a good ending in my opinion. Imagine Chris alone could have sunk the entire Soprano Family but with Carlo and his close ties on the dock and construction to New York the take down would be epic. I also think with that happening and the weight of it all on Tony to survive he flips and pulls a Joe Massino.

Tony let blood ties cloud his judgment.