olumite

@NEILJ I'm currently looking into an 09 RX450H and came across this thread. I found this youtube video for the same A pillar leak but on a RAV4. Might it be applicable to your situation?

Deepest sympathies and condolences to John's family. RIP Britprius

OP, are the new rear silencers chambered or that "free-flow"? I've found free-flow silencers to quite bad for drone low end torque loss. When I had a SS exhaust put on my 3GS at Tony Banks, I insisted on chambered silencers. The fitters may yet be able to replace the back boxes or even install baffles (sp?) which should improve the drone at 2-2.5k rpm.

I used a Leeds based company called AC Auto Locksmiths to get a spare key for my 3GS. A key, programmed to the car, and key blade cut for £160. He's mobile, came to my house to do it. Would definitely recommend.

Your exhaust is likely to have a vacuum leak behind the heatshields (just after the secondary cats). The heatshields retain water and rust the pipework. Removing the heatshields and getting the holes repaired/welded should sort it.

The mk3 GS300 3.0L V6 is direct injection only. I'm shocked that LPG is even an option due to this.

The 3rd gen GS300 is also a V6. Because the part number for the exhaust to manifold gasket is the same between the 300 and the 450H, I reckon it'd fit onto a 450H manifold would fit onto a 300, but I'm unsure if the other end would line up with the flange of the secondary cat.

The drivers side exhaust manifold is cracked on my GS300. I'm having difficulty sourcing a GS300 specific manifold (used), for less than £300 in the UK. Might an exhaust manifold from a GS450H be fitted? On average they cost £110-120 delivered.

Very nice!!

The passenger side bank on mine (2005 3GS), has a slight leak. Want to get it sorted before it becomes a severe leak. The car is 13 years old and has done 145k miles so will get both banks and all spark plug tube seals done at the same time. Lexus Leeds quoted £295. My indy, £136.

Margate?

I get 20 mpg driving around town. But get 40 mpg on the motorway. Not sure why I'm getting 5 mpg less than the rest of you around town. Maybe its the 7 miles of stop-start traffic on the hilly Bradford roads to work?

What if they offer to sell at a price that you can't refuse?

@The-Acre I paid £700 for mine. That was for 2 cats, centre box and the 2 back boxes. I stressed that they be chambered. I wasn't interested in the drone that often comes with free flow exhausts. Or the loss of low rev torque.

I've had my 05 GS300 for nearly a year now. It is a heavy NA car and on the test drive, I too thought the car was sluggish at low speed. Until I enabled ECT-PWR!! It transformed the car for me. The gearbox was much more eager to kick down in this mode. But make no mistake, a 450H would crush a 300 for speed/power. Another unintentional bonus was having some much needed engine assisted braking, which I am sure is extending the life of my disks/pads. In my first year of ownership, thus far I've put on some winter tyres, replaced the PCV valve, 2 tyre pressure sensors and had a full stainless steel exhaust system fitted. NOTE: If you replace the PCV valve, get a genuine Lexus part. I foolishly bought a cheap 3rd party one thinking it'd do the job. How wrong I was. All it did was burn oil at a frightening rate. Like almost a litre in a single 270 mile trip frightening! Ordered the Lexus part and after the return trip, the oil level on the dipstick hadn't gone down. I love my GS300, will keep it until one of us dies!