RAC advanced inspection or a full service. Which is more thorough?

facade

There is every chance that the fault is something simple, like a faulty oxygen sensor, or an (expensive) exhaust leak, but unless you are fixing it yourself, and getting the car for at least £500 less to take account of expensive parts, the seller needs to fix it before you buy it at the asking price.

It could cost £1000s at a main dealer for a fix you could do yourself for £50, why take the risk?

Mildly_Miffed

Only 23k miles in six years?

That could easily be the cause of the problem.

Goudy

It doesn't need a service, you said it's just had one.

It needs diagnostics by someone competent to identify the fault and then fixing.

After which it might be appropriate to get a general condition inspection before buying it.

If the seller isn't interested in getting it diagnosed and fixed before selling, you need to ask yourself why.
Do they already know what the problem is and they realise they wouldn't recover the repair bill in the sale price?

Also why would anyone buy it with an unknown fault.
Yes I can understand someone buying a car with a known fault and paying the appropriate price, but actually knowing it has an undiagnosed fault would put most people off enough to walk away.

It might help with a few possible suggestions if we knew the make, model and engine.
Some cars have very well known faults, others are prone to induced faults like a short tripped diesel.

Arunmor

Mildly_Miffed said:

Only 23k miles in six years?

That could easily be the cause of the problem.

Are you thinking a spot of Italian tuning?  

jimjames

You don't need a service or an inspection, just pay to take it to a main dealer or other garage that will read the fault code for you if you don't have the facility to do that yourself. Likely to be in the £100-150 bracket depending on the make of car

prowla

If it's a diesel, then it might need a good run to make it happy.

Emission warnings can be down to faulty sensors or real issues with the cat; they're devilishly difficult to diagnose and the technique of just replacing the sensors (which are usually the least reliable kit in the whole car)) may or may not resolve it.

Before doing an AA/RAC inspection, I would read the details and see what they exclude.