2002 hyundai terrecan

Hi, first time user Scott here.
I have a 2002 Hyundai Terrecan.
Just had a question thought someone might be able to help me with, The exhaust has tarted making a sound like it is restricted. When at high revs the sound increase. It doesnt happen all the time and there doesnt sem to be anything in particular that makes it happen.
I am thinking it might be an oxygen sensor fault but as I am just a backyard mechanic its a bit of a guess. Anyone have any suggestions and or way I can check the sensors.........
Thanks, any advice would be appreciated

Hi and welcome,

Their are people on here who can help, am sure one will be along soon.

Welcome scott!

Like the man says, there will be one along soon.

Forget the oxygen sensor initially, does it have a simple catalytic convertor fitted? if so then remove this and check for restrictions as they can clog up if the vehicle does a lot of short journeys and doesn't get hot enough to light up and burn the deposits away. To light up the cat you drive for about 10 miles to fully warm the engine and then pull away and rev to the red line in a couple of gears, the heat then lights it up. Drive at high engine speeds for about 10 miles, if its manual then go on the motorway at 70 MPH in a lower gear to keep the engine revs high.

Check the silencers as the internal baffles can collapse, they are perforated tube and if they collapse the silencing glass fibre wadding can collapse and a combination of the two can clog the exhaust. Check by getting under the vehicle and hitting the underside of the silencer and resonator box/boxes reasonable hard with your hand, if you hear a lot of metal moving when you hit them then remove them and empty them out.

The cats are known to go after a while, crumble and fall apart from the inside. But its cheaper to do a cat replacement pipe. And it still passes the MOT.
I did it, and it works great, MOT pass fine, and im pretty sure the emisions regs have not changed in 2 yeas.

Jas