Re: I now can get RPM's with no O2...
New, high-flow catalytic converters are available that are much smaller than the OEM units. A few years back we had to replace the single cat under our full-size Olds wagon so it would pass the smog test. The local muffler shop came in with the low bid using a generic cat rated for 300 hp V-8 engines (overkill for the wimpy Olds Rocket V-8 in the Custom Cruiser). It weighed all of 15 lbs. and was less than a foot long with huge inlet and outlet pipes. The car passed smog easily afterward, and continued to run fine. The whole job was $200. Two of those little cats would be overkill for a Range Rover, but they would work very nicely. (Yeah, they're not original, and you'll lose points in a concours, but most folks on this forum are more concerned with performance, so keep them in mind.)
Scott
"Cleaning" an O2 sensor may only solve part of the problem, but the sensors themselves become less sensitive with time, and the mixture richens as a result over time. This aging of the O2 sensors results in fuel economy going from not-so-good to just plain miserable on a Range Rover, and with the EFI light on the catalysts will clog with soot. This is why all manufacturers require replacing O2 sensors between 40,000-60,000 miles. I replaced mine with the same size O2 sensors from a Nissan V-6 pickup for a lot less than the OEM replacements, and it made quite a difference. I got them for about $55 each on-line.knie0012 said:
New, high-flow catalytic converters are available that are much smaller than the OEM units. A few years back we had to replace the single cat under our full-size Olds wagon so it would pass the smog test. The local muffler shop came in with the low bid using a generic cat rated for 300 hp V-8 engines (overkill for the wimpy Olds Rocket V-8 in the Custom Cruiser). It weighed all of 15 lbs. and was less than a foot long with huge inlet and outlet pipes. The car passed smog easily afterward, and continued to run fine. The whole job was $200. Two of those little cats would be overkill for a Range Rover, but they would work very nicely. (Yeah, they're not original, and you'll lose points in a concours, but most folks on this forum are more concerned with performance, so keep them in mind.)
Scott
