1997 Lada Riva 1.7L Petrol · P991 MKO

The Riva unibody construction was treated with minimal factory rust protection, which deteriorated rapidly in salty, damp UK winters. Corrosion aggressively attacks the inner and outer sills, jacking points, front inner wings around the headlamp bowls, lower windscreen scuttle, and rear suspension link mounting points (especially trailing arms and Panhard rod brackets). Thick, cracked aftermarket bitumen underseal often conceals terminal structural rot until an MOT inspector investigates with a corrosion probe.

To comply with 1992–1993 UK and European emissions legislation, AvtoVAZ retrofitted the Riva with an electronically monitored carburettor and a catalytic converter rather than modern electronic fuel injection. The manual choke combined with crude feedback loops frequently caused excessive over-fuelling, dumping raw fuel into the exhaust. Unburnt fuel quickly poisoned and melted the precious metals within the catalyst honeycomb, causing chronic MOT fast-idle emissions failures (DVSA codes 7.3.D.3 and 7.3.B.1a).

The Riva utilizes a worm-and-roller steering box and multi-link steering idler arrangement derived from the Fiat 124 design. While heavy at low parking speeds by modern standards, excessive rotational slack at the steering wheel is an exceptionally common UK MOT failure item (DVSA code 2.2.A.1a). Internal worm gear wear, leaking box oil seals, and perished rubber boots on the drag link and tie rod ends cause vague directional stability and dangerous high-speed wandering.