diff --git a/app/components/UI/OptinMetrics/index.js b/app/components/UI/OptinMetrics/index.js
index 525c9babc6b..3f1c8db1754 100644
--- a/app/components/UI/OptinMetrics/index.js
+++ b/app/components/UI/OptinMetrics/index.js
@@ -8,7 +8,6 @@ import {
   BackHandler,
   Alert,
   InteractionManager,
-  Platform,
 } from 'react-native';
 import PropTypes from 'prop-types';
 import { baseStyles, fontStyles } from '../../../styles/common';
@@ -24,17 +23,9 @@ import {
   MetaMetricsEvents,
   withMetricsAwareness,
 } from '../../hooks/useMetrics';
-
 import DefaultPreference from 'react-native-default-preference';
 import { ThemeContext } from '../../../util/theme';
-import generateTestId from '../../../../wdio/utils/generateTestId';
-import {
-  OPTIN_METRICS_I_AGREE_BUTTON_ID,
-  OPTIN_METRICS_NO_THANKS_BUTTON_ID,
-  OPTIN_METRICS_TITLE_ID,
-  METAMETRICS_OPT_IN_CONTAINER_ID,
-  OPTIN_METRICS_PRIVACY_POLICY_DESCRIPTION_CONTENT_1_ID,
-} from '../../../../wdio/screen-objects/testIDs/Screens/OptinMetricsScreen.testIds';
+import { MetaMetricsOptInSelectorsIDs } from '../../../../e2e/selectors/Onboarding/MetaMetricsOptIn.selectors';
 import Button, {
   ButtonVariants,
   ButtonSize,
@@ -416,7 +407,9 @@ class OptinMetrics extends PureComponent {
         <Button
           variant={ButtonVariants.Secondary}
           onPress={this.onCancel}
-          {...generateTestId(Platform, OPTIN_METRICS_NO_THANKS_BUTTON_ID)}
+          testID={
+            MetaMetricsOptInSelectorsIDs.OPTIN_METRICS_NO_THANKS_BUTTON_ID
+          }
           style={styles.button}
           label={strings('privacy_policy.cta_no_thanks')}
           size={ButtonSize.Lg}
@@ -426,7 +419,7 @@ class OptinMetrics extends PureComponent {
         <Button
           variant={ButtonVariants.Primary}
           onPress={this.onConfirm}
-          {...generateTestId(Platform, OPTIN_METRICS_I_AGREE_BUTTON_ID)}
+          testID={MetaMetricsOptInSelectorsIDs.OPTIN_METRICS_I_AGREE_BUTTON_ID}
           style={styles.button}
           label={strings('privacy_policy.cta_i_agree')}
           size={ButtonSize.Lg}
@@ -488,7 +481,7 @@ class OptinMetrics extends PureComponent {
     return (
       <SafeAreaView
         style={styles.root}
-        {...generateTestId(Platform, METAMETRICS_OPT_IN_CONTAINER_ID)}
+        testID={MetaMetricsOptInSelectorsIDs.METAMETRICS_OPT_IN_CONTAINER_ID}
       >
         <ScrollView
           style={styles.root}
@@ -500,16 +493,15 @@ class OptinMetrics extends PureComponent {
           <View style={styles.wrapper}>
             <Text
               style={styles.title}
-              {...generateTestId(Platform, OPTIN_METRICS_TITLE_ID)}
+              testID={MetaMetricsOptInSelectorsIDs.OPTIN_METRICS_TITLE_ID}
             >
               {strings('privacy_policy.description_title')}
             </Text>
             <Text
               style={styles.content}
-              {...generateTestId(
-                Platform,
-                OPTIN_METRICS_PRIVACY_POLICY_DESCRIPTION_CONTENT_1_ID,
-              )}
+              testID={
+                MetaMetricsOptInSelectorsIDs.OPTIN_METRICS_PRIVACY_POLICY_DESCRIPTION_CONTENT_1_ID
+              }
             >
               {strings('privacy_policy.description_content_1')}
             </Text>
diff --git a/app/components/Views/Settings/NetworksSettings/NetworkSettings/index.js b/app/components/Views/Settings/NetworksSettings/NetworkSettings/index.js
index 53fe41f5424..241ed74d769 100644
--- a/app/components/Views/Settings/NetworksSettings/NetworkSettings/index.js
+++ b/app/components/Views/Settings/NetworksSettings/NetworkSettings/index.js
@@ -9,8 +9,6 @@ import {
   Linking,
 } from 'react-native';
 import { connect } from 'react-redux';
-import { isSafeChainId, toHex } from '@metamask/controller-utils';
-
 import { typography } from '@metamask/design-tokens';
 import {
   fontStyles,
@@ -66,6 +64,8 @@ import {
 } from '../../../../../selectors/networkController';
 import { regex } from '../../../../../../app/util/regex';
 import { NetworksViewSelectorsIDs } from '../../../../../../e2e/selectors/Settings/NetworksView.selectors';
+import { isSafeChainId, toHex } from '@metamask/controller-utils';
+import { CustomDefaultNetworkIDs } from '../../../../../../e2e/selectors/Onboarding/CustomDefaultNetwork.selectors';
 import { updateIncomingTransactions } from '../../../../../util/transaction-controller';
 import { withMetricsAwareness } from '../../../../../components/hooks/useMetrics';
 import { CHAIN_IDS } from '@metamask/transaction-controller/dist/constants';
@@ -1250,6 +1250,7 @@ class NetworkSettings extends PureComponent {
               size={ButtonSize.Lg}
               disabled={isActionDisabled}
               width={ButtonWidthTypes.Full}
+              testID={CustomDefaultNetworkIDs.USE_THIS_NETWORK_BUTTON_ID}
             />
           ) : (
             (addMode || editable) && (
diff --git a/e2e/pages/Onboarding/DefaultNetworkView.js b/e2e/pages/Onboarding/DefaultNetworkView.js
new file mode 100644
index 00000000000..f5fecb810f5
--- /dev/null
+++ b/e2e/pages/Onboarding/DefaultNetworkView.js
@@ -0,0 +1,31 @@
+import Matchers from '../../utils/Matchers';
+import Gestures from '../../utils/Gestures';
+import NetworksView from '../Settings/NetworksView';
+import {
+  CustomDefaultNetworkIDs,
+  CustomDefaultNetworkTexts,
+} from '../../selectors/Onboarding/CustomDefaultNetwork.selectors';
+
+class DefaultNetworkView {
+  get useThisNetworkButton() {
+    return device.getPlatform() === 'ios'
+      ? Matchers.getElementByID(
+          CustomDefaultNetworkIDs.USE_THIS_NETWORK_BUTTON_ID,
+        )
+      : Matchers.getElementByLabel(
+          CustomDefaultNetworkTexts.USE_THIS_NETWORK_BUTTON_TEXT,
+        );
+  }
+
+  async tapUseThisNetworkButton() {
+    await Gestures.waitAndTap(this.useThisNetworkButton);
+    await Gestures.waitAndTap(this.useThisNetworkButton);
+  }
+
+  async typeRpcURL(rpcURL) {
+    await (await NetworksView.rpcURLInput).clearText();
+    await NetworksView.typeInRpcUrl(rpcURL);
+  }
+}
+
+export default new DefaultNetworkView();
diff --git a/e2e/pages/Onboarding/MetaMetricsOptInView.js b/e2e/pages/Onboarding/MetaMetricsOptInView.js
index a964daecdac..a2c0ab960a1 100644
--- a/e2e/pages/Onboarding/MetaMetricsOptInView.js
+++ b/e2e/pages/Onboarding/MetaMetricsOptInView.js
@@ -1,29 +1,30 @@
-import {
-  OPTIN_METRICS_I_AGREE_BUTTON_ID,
-  OPTIN_METRICS_NO_THANKS_BUTTON_ID,
-  OPTIN_METRICS_PRIVACY_POLICY_DESCRIPTION_CONTENT_1_ID,
-  METAMETRICS_OPT_IN_CONTAINER_ID,
-} from '../../../wdio/screen-objects/testIDs/Screens/OptinMetricsScreen.testIds';
+import { MetaMetricsOptInSelectorsIDs } from '../../selectors/Onboarding/MetaMetricsOptIn.selectors';
 import Matchers from '../../utils/Matchers';
 import Gestures from '../../utils/Gestures';
 
 class MetaMetricsOptIn {
   get container() {
-    return Matchers.getElementByID(METAMETRICS_OPT_IN_CONTAINER_ID);
+    return Matchers.getElementByID(
+      MetaMetricsOptInSelectorsIDs.METAMETRICS_OPT_IN_CONTAINER_ID,
+    );
   }
 
   get optInMetricsContent() {
     return Matchers.getElementByID(
-      OPTIN_METRICS_PRIVACY_POLICY_DESCRIPTION_CONTENT_1_ID,
+      MetaMetricsOptInSelectorsIDs.OPTIN_METRICS_PRIVACY_POLICY_DESCRIPTION_CONTENT_1_ID,
     );
   }
 
   get iAgreeButton() {
-    return Matchers.getElementByID(OPTIN_METRICS_I_AGREE_BUTTON_ID);
+    return Matchers.getElementByID(
+      MetaMetricsOptInSelectorsIDs.OPTIN_METRICS_I_AGREE_BUTTON_ID,
+    );
   }
 
   get noThanksButton() {
-    return Matchers.getElementByID(OPTIN_METRICS_NO_THANKS_BUTTON_ID);
+    return Matchers.getElementByID(
+      MetaMetricsOptInSelectorsIDs.OPTIN_METRICS_NO_THANKS_BUTTON_ID,
+    );
   }
 
   async tapAgreeButton() {
@@ -35,6 +36,15 @@ class MetaMetricsOptIn {
     await Gestures.swipe(this.optInMetricsContent, 'up', 'fast', 0.9);
     await Gestures.waitAndTap(this.noThanksButton);
   }
+
+  async tapEditDefaultNetworkHere() {
+    await Gestures.swipe(this.optInMetricsContent, 'up', 'fast', 0.9);
+    if (device.getPlatform() === 'ios') {
+      await Gestures.tapAtPoint(this.container, { x: 333, y: 534 });
+    } else {
+      await Gestures.tapAtPoint(this.optInMetricsContent, { x: 15, y: 570 });
+    }
+  }
 }
 
 export default new MetaMetricsOptIn();
diff --git a/e2e/resources/blacklistURLs.json b/e2e/resources/blacklistURLs.json
index 1701ce9b7f0..df2c6cfb137 100644
--- a/e2e/resources/blacklistURLs.json
+++ b/e2e/resources/blacklistURLs.json
@@ -8,6 +8,8 @@
     ".*rpc.tenderly.co/.*",
     ".*api-goerli.etherscan.io/.*",
     ".*cloudflare-ipfs.com/.*",
-    ".*stale.*"
+    ".*stale.*",
+    ".*phishing-detection.metafi.codefi.network/.*",
+    ".*token-api.metaswap.codefi.network/.*"
   ]
 }
diff --git a/e2e/resources/networks.json b/e2e/resources/networks.json
index 9b8278ae68d..6cce343759e 100644
--- a/e2e/resources/networks.json
+++ b/e2e/resources/networks.json
@@ -71,5 +71,14 @@
       "nickname": "Gnosis",
       "ticker": "xDAI"
     }
+  },
+  "EthereumMainCustom": {
+    "providerConfig": {
+      "type": "rpc",
+      "chainId": "1",
+      "rpcUrl": "https://eth.llamarpc.com",
+      "nickname": "Ethereum Main Custom",
+      "ticker": "ETH"
+    }
   }
 }
diff --git a/e2e/selectors/Onboarding/CustomDefaultNetwork.selectors.js b/e2e/selectors/Onboarding/CustomDefaultNetwork.selectors.js
new file mode 100644
index 00000000000..e3483e8aec9
--- /dev/null
+++ b/e2e/selectors/Onboarding/CustomDefaultNetwork.selectors.js
@@ -0,0 +1,9 @@
+import messages from '../../../locales/languages/en.json';
+
+export const CustomDefaultNetworkIDs = {
+  USE_THIS_NETWORK_BUTTON_ID: 'use-this-network',
+};
+
+export const CustomDefaultNetworkTexts = {
+  USE_THIS_NETWORK_BUTTON_TEXT: messages.app_settings.networks_default_cta,
+};
diff --git a/e2e/selectors/Onboarding/MetaMetricsOptIn.selectors.js b/e2e/selectors/Onboarding/MetaMetricsOptIn.selectors.js
new file mode 100644
index 00000000000..64679ae3bde
--- /dev/null
+++ b/e2e/selectors/Onboarding/MetaMetricsOptIn.selectors.js
@@ -0,0 +1,13 @@
+// eslint-disable-next-line import/prefer-default-export
+export const MetaMetricsOptInSelectorsIDs = {
+  OPTIN_METRICS_TITLE_ID: 'optin-metrics-title-id',
+  OPTIN_METRICS_NO_THANKS_BUTTON_ID: 'optin-metrics-no-thanks-button-id',
+  OPTIN_METRICS_I_AGREE_BUTTON_ID: 'optin-metrics-i-agree-button-id',
+  OPTIN_METRICS_PRIVACY_POLICY_DESCRIPTION_CONTENT_1_ID:
+    'optin-metrics-privacy-policy-description',
+  OPTIN_METRICS_HERE_DEFAULT_NETWORK_ID: 'optin-metrics-default-network-id',
+  DEFAULT_NETWORK_RPC_URL: 'default-network-rpc-url',
+  DEFAULT_NETWORK_USE_THIS_NETWORK_BUTTON_ID:
+    'default-network-use-this-button-id',
+  METAMETRICS_OPT_IN_CONTAINER_ID: 'meta-metrics-container',
+};
diff --git a/e2e/specs/onboarding/add-custom-eth-mainnet.spec.js b/e2e/specs/onboarding/add-custom-eth-mainnet.spec.js
new file mode 100644
index 00000000000..795aacb1d80
--- /dev/null
+++ b/e2e/specs/onboarding/add-custom-eth-mainnet.spec.js
@@ -0,0 +1,60 @@
+import { Regression } from '../../tags';
+import OnboardingCarouselView from '../../pages/Onboarding/OnboardingCarouselView';
+import OnboardingView from '../../pages/Onboarding/OnboardingView';
+import Assertions from '../../utils/Assertions';
+import MetaMetricsOptIn from '../../pages/Onboarding/MetaMetricsOptInView';
+import DefaultNetworkView from '../../pages/Onboarding/DefaultNetworkView';
+import TermsOfUseModal from '../../pages/modals/TermsOfUseModal';
+import CreatePasswordView from '../../pages/Onboarding/CreatePasswordView';
+import EnableAutomaticSecurityChecksView from '../../pages/EnableAutomaticSecurityChecksView';
+import SkipAccountSecurityModal from '../../pages/modals/SkipAccountSecurityModal';
+import WalletView from '../../pages/WalletView';
+import ProtectYourWalletView from '../../pages/Onboarding/ProtectYourWalletView';
+import NetworksView from '../../pages/Settings/NetworksView';
+import Accounts from '../../../wdio/helpers/Accounts';
+import { DEFAULT_MAINNET_CUSTOM_NAME } from '../../../app/constants/network';
+import Networks from '../../resources/networks.json';
+
+const validAccount = Accounts.getValidAccount();
+
+describe(Regression('Add custom default ETH Mainnet'), () => {
+  beforeAll(async () => {
+    await device.launchApp();
+  });
+
+  it('should navigate to edit custom default ETH Mainnet from Opt-In screen', async () => {
+    await OnboardingCarouselView.tapOnGetStartedButton();
+    await OnboardingView.tapCreateWallet();
+    await Assertions.checkIfVisible(MetaMetricsOptIn.container);
+  });
+
+  it('should not edit default network with invalid RPC', async () => {
+    await MetaMetricsOptIn.tapEditDefaultNetworkHere();
+    await DefaultNetworkView.typeRpcURL('https//rpc.mevblocker.io');
+    await Assertions.checkIfVisible(NetworksView.rpcWarningBanner);
+  });
+
+  it('should edit default ETH Mainnet with valid RPC', async () => {
+    await DefaultNetworkView.typeRpcURL(
+      Networks.EthereumMainCustom.providerConfig.rpcUrl,
+    );
+    await DefaultNetworkView.tapUseThisNetworkButton();
+    await Assertions.checkIfVisible(MetaMetricsOptIn.container);
+  });
+
+  it('should show custom default ETH Mainnet as active', async () => {
+    await MetaMetricsOptIn.tapAgreeButton();
+    await TermsOfUseModal.tapScrollEndButton();
+    await TermsOfUseModal.tapAgreeCheckBox();
+    await TermsOfUseModal.tapAcceptButton();
+    await CreatePasswordView.enterPassword(validAccount.password);
+    await CreatePasswordView.reEnterPassword(validAccount.password);
+    await CreatePasswordView.tapIUnderstandCheckBox();
+    await CreatePasswordView.tapCreatePasswordButton();
+    await ProtectYourWalletView.tapOnRemindMeLaterButton();
+    await SkipAccountSecurityModal.tapIUnderstandCheckBox();
+    await SkipAccountSecurityModal.tapSkipButton();
+    await EnableAutomaticSecurityChecksView.tapNoThanks();
+    await WalletView.isNetworkNameVisible(DEFAULT_MAINNET_CUSTOM_NAME);
+  });
+});