Engine Rattling And Whining Sounds problems of the 2005 Nissan Quest

I've had this vehicle into my local Nissan dealers service center many times for a loss of power. They had me replace the ecu, which had to be programmed, then they said that it was the catalytic converters. I bought all three of those. After that it needed to be programmed for the air/fuel ratio. Still ran the same. I brought it into a different shop, they said it had a bad throttle. My brother had one I had put in but still no power, and hesitation at acceleration and up hills, and misfires and backfires a lot. One of the codes they found for me was a timing issue. My brother has same van told me he had to replace the timing chain. I've heard a rattling and whining noise from timing area, so I looked into this further. Back in 2004 Nissan issued a TSB regarding this issue telling technicians to make a "goodwill adjustment" to push back repairs of this issue until the vehicle was out of warranty. I am very concerned about this problem with my vehicle since learning about what could happen should it fail. I drive my children in that van and bought it because I thought it would be a safe and comfortable vehicle to drive. Apparently not. Nissan consumer affairs even told me that they will not cover the cost of repairs. I currently await to hear from a supervisor to give them an earful and to find out the reasons why it will not be fixed. This should be a safety recall. If catastrophic engine failure due to this happens on the highway (which we travel almost every day), this would leave the vehicle completely crippled and unable to steer out of the way of any danger. Sooner or later someone is going to be injured if not killed in a motor vehicle accident from this if not already. It's a shame Nissan doesn't see the value of potentially saving its customers lives vs. The cost of making necessary repairs. It should be a recall. I'll never buy a Nissan again.

The engine makes a rattling noise. Dealer says timing chain guide needs to be replace at a cost of $1700. They also asked me not to drive the vehicle as it may cause the timing chain to jump in the middle of the road causing an accident and also engine damage.