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2002 Dodge Grand Caravan P0455 and P0422 Error: Gas Gauge Drops to E at 1/4 Tank - EVAP Leak & Fuel Level Sensor Issues

Model: 2002 dodge caravan Fault Code: P0422 Posted: 2007-10-02 18:35

My wife and I own a 2002 Dodge Grand Caravan with a 3.3L V6 engine. A few weeks ago, she noticed that once the fuel gauge reached one-quarter tank, it would suddenly drop to 'E' (empty) without any visible reason. Yesterday, the check engine light turned on, and an OBD-II scan revealed two fault codes: P0455 (Evaporative Emission System Leak Detected - Large Leak) and P0422 (Catalyst Efficiency Below Threshold for Bank 1). We’ve already checked the air cleaner box and didn’t find any cracked hoses. The vehicle is under a 100,000-mile warranty with a $100 deductible. While we’d prefer to fix this ourselves if it’s a simple repair, we’re unsure whether the erratic fuel gauge behavior is related to these engine codes. Could a faulty gas cap or evaporative system leak be causing both the P0455 code and the incorrect fuel gauge reading? We’ve seen similar issues in other forums and suspect that a failing leak detection pump (LDP) or a loose EVAP line might be at fault. Any guidance on diagnosing this issue—especially whether replacing the gas cap or inspecting the fuel tank sender could resolve both symptoms—would be greatly appreciated.

Related fault codes

P0422P0455

Comments (9)

Anonymous 2007-10-03 07:42

The P0455 code indicates a significant evaporative emission system leak, likely in the EVAP system. The P0422 code suggests that the catalytic converter for Bank 1 is not performing efficiently—possibly due to upstream issues or contamination. These codes are typically linked to an EVAP leak, which can also affect fuel level readings if vacuum pressure in the tank fluctuates.

Anonymous 2007-10-03 08:25

A malfunctioning Leak Detection Pump (LDP) or a faulty gas cap is a common cause of both P0455 and erratic fuel gauge behavior. To test this, simply remove the gas cap and monitor whether the fuel gauge returns to normal. If it does, the issue is likely due to a loose or defective cap. A new cap from the dealer can be a low-cost fix—this is one of the most common causes of EVAP-related codes in 2002 Dodge Grand Caravans.

Anonymous 2007-10-03 10:01

We purchased an extended warranty when we bought our used vehicle about a year ago and have had several issues resolved without cost. The coverage ends at 100,000 miles—just 8,000 miles away. If this issue seems serious, I’ll bring it to the dealership for service. As a new forum user, could you explain what an LDP and TSB are? Thanks!

Anonymous 2007-10-03 13:08

LDP stands for Leak Detection Pump—a component in the EVAP system that detects leaks by monitoring vacuum pressure. A TSB (Technical Service Bulletin) is a document issued by the manufacturer outlining known issues and recommended fixes for specific vehicle models or problems.

Anonymous 2007-10-11 22:15

Hi Jeff—thanks for your reply! I have a question: Can a bad gas cap cause a malfunction in the fuel level sensor? If so, how would that affect the gauge reading?

Anonymous 2007-10-12 05:57

Excessive vacuum pressure inside the fuel tank can interfere with the float mechanism of the fuel level sender, leading to inaccurate readings—such as dropping from 1/4 to empty when it shouldn’t.

Anonymous 2007-12-27 13:27

I own a 2001 Dodge Ram 1500 and experienced identical P0455 and P0422 codes. The large hose connecting the fuel tank to the EVAP system had dried, cracked, and was leaking fumes. This caused both the erratic fuel gauge and the check engine light. I eventually had to remove the fuel tank to replace a failed plastic float and repair the hose. I now use an OBD-II scanner due to repeated failures. As a side note, my engine failed at 92,000 miles from compression failure in cylinders 4 and 6. I will not purchase another Chrysler vehicle—there are too many mechanical issues over short distances. I’ve been loyal to Chrysler for years, owning vintage cars, a Dodge Fargo motorhome, and multiple Chrysler models. The quality control seems inconsistent across their lineup.

Anonymous 2007-12-27 16:10

Chrysler now offers a lifetime warranty—but that doesn’t make it reliable. Show me a product that’s perfect and affordable for the average consumer, and I’ll start selling them instead of fixing cars. This post reads more like a general complaint about Chrysler than a helpful repair guide. The point of this forum is to provide actionable advice—not just criticism. Please focus on technical solutions when posting.

Anonymous 2008-02-04 18:19

Shortly after my last comment, the check engine light went out and didn’t return until now—mileage at that time was 100,050. How strange is it that the issue reappeared right after our warranty expired? I suspect this might be a deliberate programming behavior. I’m glad most of my other vehicles are from the 1990s. Thanks for all the help—I hope we can fix this without major hassle from the dealership.