Have you ever been driving your lovely Audi when suddenly that pesky check engine light pops on? Next thing you know, your mechanic is talking about something called a “P17D800 fault code” and your eyes glaze over. Don’t worry – you’re not alone! That’s why we’ve put together this handy guide to break down what this fault code means, why it happens, and how we can help sort it for you.

 

What Exactly Is the P17D800 Audi Fault Code?

Simply put, the P17D800 fault code in Audi vehicles is related to the exhaust gas recirculation (EGR) system. This system helps reduce harmful emissions from your car by recycling some exhaust gases back into the engine. When your car’s computer detects a problem with this system, it triggers the P17D800 code.

Think of it like this: your car has its own little detective agency constantly checking that everything’s working properly. When it spots something fishy with the EGR system, it raises the alarm by turning on your check engine light and storing this code.

 

Why Should You Care About This Fault Code?

You might be wondering, “Do I really need to worry about this?” The short answer is yes, and here’s why:

1. It affects your car’s performance – You might notice your engine running roughly, especially when idling.
2. It can reduce fuel efficiency – Your Audi might start guzzling more fuel than usual.
3. It increases harmful emissions – Not great for the environment or for passing your MOT test.
4. It could lead to bigger problems – Ignoring it might result in more expensive repairs down the line.

The P17D800 fault code is one of the more common issues in models manufactured between 2015-2022.

 

Common Causes of the P17D800 Fault Code

So what’s actually going wrong when this code appears? Here are the most common culprits:

 

1. Clogged EGR Valve

The EGR valve can get blocked with carbon deposits over time. Think of it like the limescale that builds up in your kettle – except this buildup affects how your car runs!

 

2. Faulty EGR Valve

Sometimes the valve itself is broken or not opening and closing properly. According to research from the European Automobile Manufacturers’ Association, about 35% of EGR-related issues are due to valve failures.

 

3. Damaged Electrical Connections

The wires and connectors that tell the EGR system what to do can become damaged or corroded.

 

4. Sensor Problems

Various sensors monitor your EGR system, and when they go wonky, they can trigger fault codes even if the system itself is fine.

 

5. Software Issues

Sometimes the problem isn’t hardware at all – it might be a glitch in your car’s computer system.

 

Symptoms You Might Notice

How do you know if you’re experiencing this fault code? Watch out for these signs:

Symptom	Severity	Common in Models
Engine management light on	Moderate	All Audi models
Rough idling	Moderate	A3, A4, Q3
Reduced power (limp mode)	High	A6, Q5, Q7
Poor fuel economy	Low-Moderate	All models
Failed emissions test	High	All models
Engine stalling	High	TT, A1, A3

If you’re noticing any of these symptoms, it’s time to get your Audi checked by a specialist. You can contact us to book an appointment with our Audi experts right away.

 

How We Diagnose the P17D800 Fault Code

At First Auto Centre, our approach to diagnosing this fault code is thorough and methodical. Here’s what our car diagnostics process looks like:

1. Advanced Diagnostic Scanning – We use genuine Audi-compatible diagnostic equipment to read the specific fault code and any related codes that might be present.
2. Visual Inspection – Our technicians physically examine the EGR system, looking for obvious signs of damage or wear.
3. System Testing – We test the operation of the EGR valve and related components to see exactly where the problem lies.
4. Comprehensive Check – We don’t just look at the EGR system – we check related systems too, because sometimes the root cause isn’t what you’d expect!

According to Motor Industry Facts, proper diagnostic procedures identify the correct issue in about 95% of cases, which is why we never skip steps.

 

How We Fix the P17D800 Fault Code

Once we’ve pinpointed the exact cause of your P17D800 fault code, we can get to work fixing it. Here are the most common repairs we perform:

 

EGR Valve Cleaning

If your valve is just clogged up with carbon deposits, a good cleaning might be all it needs. This is often the most cost-effective solution.

 

EGR Valve Replacement

When cleaning isn’t enough, we’ll fit a new genuine or high-quality equivalent EGR valve. As Audi specialists, we ensure all parts meet or exceed manufacturer specifications.

 

Wiring Repairs

If damaged wiring is the culprit, we’ll repair or replace the affected wiring harness or connectors.

 

Sensor Replacement

Faulty sensors are more common than you might think! We’ll replace any dodgy sensors with quality new ones.

 

Software Updates

Sometimes the fix is as simple as updating your car’s software – like when you update your phone to fix bugs.

 

Preventing Future EGR Problems

Want to avoid seeing that P17D800 code again? Here are some top tips:

1. Regular Car Servicing – Keeping up with your Audi’s service schedule helps catch issues before they become problems.
2. Quality Fuel – Using better-quality fuel can reduce carbon build-up in your engine and EGR system.
3. Regular Longer Drives – Short journeys don’t let your engine reach optimal temperature, which can lead to carbon build-up. The occasional longer drive can help clear things out.
4. Prompt Attention to Warning Lights – If your check engine light comes on, don’t ignore it! Getting it checked promptly can save you money in the long run.

According to Transport Research Laboratory, regular maintenance can extend the life of EGR systems by up to 60%.

 

Why Choose First Auto Centre for Your Audi Repairs?

When your Audi displays the P17D800 fault code, you want someone who really knows what they’re doing. Here’s why our customers trust us:

1. Audi Specialists – Our technicians are specifically trained to work on Audi vehicles. Check out our Audi specialist services page.
2. Latest Diagnostic Equipment – We use the same diagnostic technology as main dealers, but without the hefty price tag.
3. Genuine and OEM Parts – We only use parts that meet or exceed Audi’s specifications.
4. Clear Communication – We explain everything in plain English, not confusing technical jargon.
5. Warranty-Backed Work – All our repairs come with a comprehensive warranty for your peace of mind.

 

Cost of Repairing P17D800 Fault Code

One of the most common questions we get is about cost. While every repair is different, here’s a rough guide to what you might expect to pay:

Repair Type	Estimated Cost Range	Typical Time Required
Diagnostic scan	£50-£85	30-60 minutes
EGR valve cleaning	£80-£150	1-2 hours
EGR valve replacement	£180-£450	1-3 hours
Wiring repairs	£70-£200	1-3 hours
Sensor replacement	£90-£250	1-2 hours
Software update	£60-£120	30-60 minutes

Remember, these are just estimates. The actual cost will depend on your specific Audi model and the exact nature of the problem. We always provide a clear quote before beginning any work.

 

Frequently Asked Questions About P17D800 Audi Fault Code

 

Can I still drive my Audi with the P17D800 fault code?

While your car might still run, it’s not recommended to drive it for extended periods with this fault code. You might experience reduced performance, poor fuel economy, and could potentially cause more damage. It’s best to get it checked at an Audi specialist as soon as possible.

 

Will the P17D800 code clear itself?

In rare cases, if it was triggered by a temporary glitch, the code might clear itself after several driving cycles. However, this is unlikely, and the problem usually requires proper car diagnostics and repair.

 

Does the P17D800 fault affect my Audi warranty?

If your Audi is still under warranty, the P17D800 fault should be covered. However, if the issue was caused by poor maintenance or using non-approved parts or services, it might affect your warranty coverage. At First Auto Centre, our Audi car servicing won’t invalidate your manufacturer warranty.

 

How long does it take to fix the P17D800 fault code?

Most repairs can be completed within a day, often in just a few hours. We’ll always give you an estimated completion time when you book your car in.

 

Is the P17D800 fault code specific to certain Audi models?

While this fault code can appear in any Audi with an EGR system, it’s more common in diesel models, particularly the A3, A4, A6, and Q5 ranges.

 

Can I fix the P17D800 fault code myself?

Unless you have specific automotive diagnostic equipment and technical knowledge, this isn’t a DIY job. The EGR system is complex and often requires specialist tools and expertise to diagnose and repair correctly.

 

Ready to Get Your Audi Fixed?

If your Audi is displaying the P17D800 fault code or any other issues, don’t wait until it gets worse. Our team of Audi specialists are ready to help.

Remember, when it comes to your Audi, catching problems early doesn’t just save you money – it keeps your car performing at its best for years to come.